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21 <td width="30%" align="right">$Date: 2002/09/04 13:58:24 $</td>
26 <h1>Frequently Asked Questions About Fetchmail</h1>
28 <p>Before reporting any bug, please read <a href="#G3">G3</a> for
29 advice on how to include diagnostic information that will get your
30 bug fixed as quickly as possible.</p>
32 <p>If you have a question or answer you think ought to be added to
33 this FAQ list, mail it to fetchmail's maintainer, Eric S. Raymond,
34 at <a href="mailto:esr@thyrsus.com">esr@thyrsus.com</a>.</p>
36 <h1>General questions:</h1>
38 <a href="#G1">G1. What is fetchmail and why should I bother?</a><br/>
39 <a href="#G2">G2. Where do I find the latest FAQ and fetchmail sources?</a><br/>
40 <a href="#G3">G3. I think I've found a bug. Will you fix it?</a><br/>
41 <a href="#G4">G4. I have this idea for a neat feature. Will you add it?</a><br/>
42 <a href="#G5">G5. I want to make fetchmail behave like Outlook Express.</a><br/>
43 <a href="#G6">G6. Is there a mailing list for exchanging tips?</a><br/>
44 <a href="#G7">G7. So, what's this I hear about a fetchmail paper?</a><br/>
45 <a href="#G8">G8. What is the best server to use with fetchmail?</a><br/>
46 <a href="#G9">G9. What is the best mail program to use with fetchmail?</a><br/>
47 <a href="#G10">G10. How can I avoid sending my password en clair?</a><br/>
48 <a href="#G11">G11. Is any special configuration needed to use a dynamic IP address?</a><br/>
49 <a href="#G12">G12. Is any special configuration needed to use firewalls?</a><br/>
50 <a href="#G13">G13. Is any special configuration needed to <em>send</em> mail?</a><br/>
51 <a href="#G14">G14. Is fetchmail Y2K-compliant?</a><br/>
52 <a href="#G15">G15. Is there a way in fetchmail to support disconnected IMAP mode?</a><br/>
53 <a href="#G16">G16. How will fetchmail perform under heavy loads?</a><br/>
56 <h1>Build-time problems:</h1>
58 <a href="#B1">B1. Make coughs and dies when building on FreeBSD.</a><br/>
59 <a href="#B2">B2. Lex bombs out while building the fetchmail lexer.</a><br/>
60 <a href="#B3">B3. I get link failures when I try to build fetchmail.</a><br/>
61 <a href="#B4">B4. I get build failures in the intl directory.</a><br/>
63 <h1>Fetchmail configuration file grammar questions:</h1>
65 <a href="#F1">F1. Why does my old .fetchmailrc no longer work?</a><br/>
66 <a href="#F2">F2. The .fetchmailrc parser won't accept my all-numeric user name.</a><br/>
67 <a href="#F3">F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.</a><br/>
68 <a href="#F4">F4. I'm getting a `parse error' message I don't understand.</a><br/>
70 <h1>Configuration questions:</h1>
72 <a href="#C1">C1. Why do I need a .fetchmailrc when running as root
73 on my own machine?</a><br/>
74 <a href="#C2">C2. How can I arrange for a fetchmail daemon to get
75 killed when I log out?</a><br/>
76 <a href="#C3">C3. How do I know what interface and address to use
77 with --interface?</a><br/>
78 <a href="#C4">C4. How can I set up support for sendmail's anti-spam
80 <a href="#C5">C5. How can I poll some of my mailboxes more/less
81 often than others?</a><br/>
82 <a href="#C6">C6. Fetchmail works OK started up manually, but not
83 from an init script.</a><br/>
84 <a href="#C7">C7. How can I forward mail to another
88 <h1>How to make fetchmail play nice with various MTAs:</h1>
90 <a href="#T1">T1. How can I use fetchmail with sendmail?</a><br/>
91 <a href="#T2">T2. How can I use fetchmail with qmail?</a><br/>
92 <a href="#T3">T3. How can I use fetchmail with exim?</a><br/>
93 <a href="#T4">T4. How can I use fetchmail with smail?</a><br/>
94 <a href="#T5">T5. How can I use fetchmail with SCO's MMDF?</a><br/>
95 <a href="#T6">T6. How can I use fetchmail with Lotus Notes?</a><br/>
96 <a href="#T7">T7. How can I use fetchmail with Courier IMAP?</a><br/>
97 <a href="#T8">T8. How can I use fetchmail with vbmailshield?</a><br/>
99 <h1>How to make fetchmail work with various servers:</h1>
101 <a href="#S1">S1. How can I use fetchmail with qpopper?</a><br/>
102 <a href="#S2">S2. How can I use fetchmail with Microsoft
104 <a href="#S3">S3. How can I use fetchmail with Compuserve
106 <a href="#S4">S4. How can I use fetchmail with Demon Internet's
108 <a href="#S5">S5. How can I use fetchmail with usa.net's
110 <a href="#S6">S6. How can I use fetchmail with HP
112 <a href="#S7">S7. How can I use fetchmail with geocities POP3
114 <a href="#S8">S8. How can I use fetchmail with Hotmail?</a><br/>
115 <a href="#S9">S9. How can I use fetchmail with MSN?</a><br/>
116 <a href="#S10">S10. How can I use fetchmail with SpryNet?</a><br/>
117 <a href="#S11">S11. How can I use fetchmail with FTGate?</a><br/>
118 <a href="#S12">S12. How can I use fetchmail with MailMax?</a><br/>
119 <a href="#S13">S13. How can I use fetchmail with Novell
121 <a href="#S14">S14. How can I use fetchmail with
122 InterChange?</a><br/>
123 <a href="#S15">S15. How can I use fetchmail with GMX?</a><br/>
126 <h1>How to set up well-known security and authentication
129 <a href="#K1">K1. How can I use fetchmail with SOCKS?</a><br/>
130 <a href="#K2">K2. How can I use fetchmail with IPv6 and
132 <a href="#K3">K3. How can I get fetchmail to work with
134 <a href="#K4">K4. What do I have to do to use the IMAP-GSS
136 <a href="#K5">K5. How can I use fetchmail with SSL?</a><br/>
139 <h1>Runtime fatal errors:</h1>
141 <a href="#R1">R1. Fetchmail isn't working, and -v shows `SMTP
142 connect failed' messages.</a><br/>
143 <a href="#R2">R2. When I try to configure an MDA, fetchmail doesn't
145 <a href="#R3">R3. Fetchmail dumps core when given an invalid rc
147 <a href="#R4">R4. Fetchmail dumps core in -V mode, but operates
148 normally otherwise.</a><br/>
149 <a href="#R5">R5. Running fetchmail in daemon mode doesn't
151 <a href="#R6">R6. Fetchmail randomly dies with socket
153 <a href="#R7">R7. Fetchmail running as root stopped working after
154 an OS upgrade</a><br/>
155 <a href="#R8">R8. Fetchmail is timing out after fetching certain
156 messages but before deleting them</a><br/>
157 <a href="#R9">R9. Fetchmail is timing out during message
159 <a href="#R10">R10. Fetchmail is dying with SIGPIPE.</a><br/>
160 <a href="#R11">R11. My server is hanging up or emitting errors on
164 <h1>Hangs and lockups:</h1>
166 <a href="#H1">H1. Fetchmail hangs when used with pppd.</a><br/>
167 <a href="#H2">H2. Fetchmail hangs during the MAIL FROM
169 <a href="#H3">H3. Fetchmail hangs while fetching mail.</a><br/>
172 <h1>Disappearing mail:</h1>
174 <a href="#D1">D1. I think I've set up fetchmail correctly, but I'm
175 not getting any mail.</a><br/>
176 <a href="#D2">D2. All my mail seems to disappear after a dropped
178 <a href="#D3">D3. Mail that was being fetched when I interrupted my
179 fetchmail seems to have been vanished.</a><br/>
182 <h1>Multidrop-mode problems:</h1>
184 <a href="#M1">M1. I've declared local names, but all my multidrop
185 mail is going to root anyway.</a><br/>
186 <a href="#M2">M2. I can't seem to get fetchmail to route to a local
187 domain properly.</a><br/>
188 <a href="#M3">M3. I tried to run a mailing list using multidrop,
189 and I have a mail loop!</a><br/>
190 <a href="#M4">M4. My multidrop fetchmail seems to be having DNS
192 <a href="#M5">M5. I'm seeing long DNS delays before each message is
194 <a href="#M6">M6. How do I get multidrop mode to work with
196 <a href="#M7">M7. Multidrop mode isn't parsing envelope addresses
197 from my Received headers as it should.</a><br/>
198 <a href="#M8">M8. Users are getting multiple copies of
202 <h1>Mangled mail:</h1>
204 <a href="#X1">X1. Spurious blank lines are appearing in the headers
205 of fetched mail.</a><br/>
206 <a href="#X2">X2. My mail client can't see a Subject
208 <a href="#X3">X3. Messages containing "From" at start of line are
209 being split.</a><br/>
210 <a href="#X4">X4. My mail is being mangled in a new and different
212 <a href="#X5">X5. Using POP3, retrievals seems to be fetching too
214 <a href="#X6">X6. My mail attachments are being dropped or
216 <a href="#X7">X7. Some mail attachments are hanging
218 <a href="#X8">X8. A spurious ) is being appended to my
222 <h1>Other problems:</h1>
224 <a href="#O1">O1. The --logfile option doesn't work if the logfile
225 doesn't exist.</a><br/>
226 <a href="#O2">O2. Every time I get a POP or IMAP message the header
227 is dumped to all my terminal sessions.</a><br/>
228 <a href="#O3">O3. Does fetchmail reread its rc file every poll
230 <a href="#O4">O4. Why do deleted messages show up again when I take
231 a line hit while downloading?</a><br/>
232 <a href="#O5">O5. Why is fetched mail being logged with my name,
233 not the real From address?</a><br/>
234 <a href="#O6">O6. I'm seeing long sendmail delays or hangs near the
235 start of each poll cycle.</a><br/>
236 <a href="#O7">O7. Why doesn't fetchmail deliver mail in date-sorted
238 <a href="#O8">O8. I'm using pppd. Why isn't my monitor option
240 <a href="#O9">O9. Why does fetchmail keep retrieving the same
241 messages over and over?</a><br/>
242 <a href="#O10">O10. Why is the received date on all my messages the
249 <h2><a id="G1" name="G1">G1. What is fetchmail and why should I
252 <p>Fetchmail is a one-stop solution to the remote mail retrieval
253 problem for Unix machines, quite useful to anyone with an
254 intermittent PPP or SLIP connection to a remote mailserver. It can
255 collect mail using any variant of POP or IMAP and forwards via port
256 25 to the local SMTP listener, enabling all the normal
257 forwarding/filtering/aliasing mechanisms that would apply to local
258 mail or mail arriving via a full-time TCP/IP connection.</p>
260 <p>Fetchmail is not a toy or a coder's learning exercise, but an
261 industrial-strength tool capable of transparently handling every
262 retrieval demand from those of a simple single-user ISP connection
263 up to mail retrieval and rerouting for an entire client domain.
264 Fetchmail is easy to configure, unobtrusive in operation, powerful,
265 feature-rich, and well documented.</p>
267 <p>Fetchmail is <a href="http://www.opensource.org">open-source</a>
268 software. The openness of the sources is the strongest assurance of
269 quality you can have. Extensive peer review by a large,
270 multi-platform user community has shown that fetchmail is as near
271 bulletproof as the underlying protocols permit.</p>
273 <p>Fetchmail is licensed under the <a
274 href="http://gnu.org//copyleft/gpl.html">GNU General Public
277 <p>If you found this FAQ in the distribution, see the README for
278 fetchmail's full feature list.</p>
281 <h2><a id="G2" name="G2">G2. Where do I find the latest FAQ and
282 fetchmail sources?</a></h2>
284 <p>The latest HTML FAQ is available alongside the latest fetchmail
285 sources at the fetchmail home page: <a
286 href="http://www.tuxedo.org/~esr/fetchmail">http://www.tuxedo.org/~esr/fetchmail</a>.
287 You can also usually find both in the <a
288 href="http://sunsite.unc.edu/pub/Linux/system/mail/pop/!INDEX.html">
289 POP mail tools directory on Sunsite</a>.</p>
291 <p>A text dump of this FAQ is included in the fetchmail
292 distribution. Because it freezes at distribution release time, it
293 may not be completely current.</p>
296 <h2><a id="G3" name="G3">G3. I think I've found a bug. Will you fix
299 <p>Yes I will, provided you include enough diagnostic information
300 for me to go on. Send bugs to <a
301 href="mailto:fetchmail-friends@ccil.org">fetchmail-friends</a>.
302 When reporting bugs, please include the following:</p>
305 <li>Your operating system.</li>
307 <li>Your compiler version, if you built from source; otherwise, the
308 name and origin of the RPM or other binary package you
311 <li>A copy of your POP or IMAP server's greeting line.</li>
313 <li>The name and version of the SMTP listener or MDA you are
316 <li>Any command-line options you used.</li>
318 <li>The output of fetchmail -V called with whatever other
319 command-line options you used.</li>
322 <p>If you have FTP access to your remote mail account, and you have
323 any suspicion that the bug was triggered by a particular message,
324 please include a copy of the message that triggered the bug.</p>
326 <p>Often, the first thing I will do when you report a bug is tell
327 you to upgrade to the newest version of fetchmail, and then see if
328 the problem reproduces. So you'll probably save us both time if you
329 upgrade and test with the latest version <em>before</em> sending in
332 <p>If your bug is something that used to work but stopped working
333 when you upgraded, then you can help pin the bug down by trying <a
334 href="ftp://ftp.ccil.org/pub/esr/fetchmail/">intermediate versions
335 of fetchmail</a> until you identify the revision that broke your
336 feature. The smart way to do this is by binary search on the
337 version sequence. First, try the version halfway between your last
338 good one and the current one. If it works, the failure was
339 introduced in the upper half of the sequence; if it doesn't, the
340 failure was introduced in the lower half. Now bisect that half in
341 the same way. In a very few tries, you should be able to identify
342 the exact adjacent pair of versions between which your bug was
343 introduced -- and with information like that, I can usually come up
344 with a fix very quickly.</p>
346 <p>Another useful thing you can do, if you're using POP3, is to
347 test for IMAP4 support on your mailserver using the autoprobe
348 function of fetchmailconf. If you have IMAP4, and fetchmailconf
349 doesn't tell you it's broken, switch immediately. POP3 is a weak,
350 poorly-designed protocol with chronic problems, and the later
351 versions after RFC1725 actually get worse rather than better.
352 Changing over to IMAP4 may well make your problem go away -- and if
353 your ISP doesn't have IMAP4 support, bug them to supply it.</p>
355 <p>It is helpful if you include your .fetchmailrc file, but not
356 necessary unless your symptom seems to involve an error in
357 configuration parsing. If you do send in your .fetchmailrc, mask
358 the passwords first!</p>
360 <p>If fetchmail seems to run and fetch mail, but the headers look
361 mangled (that is, headers are missing or blank lines are inserted
362 in the headers) then read the FAQ items in section <a
363 href="#X1">X</a> before submitting a bug report. Pay special
364 attention to the item on <a href="#generic_mangling">diagnosing
365 mail mangling</a>. There are lots of ways for other programs in the
366 mail chain to screw up that look like fetchmail's fault, but you
367 may be able to fix these by tweaking your configuration.</p>
369 <p>A transcript of the failed session with -v -v (yes, that's
370 <em>two</em> -v options, enabling debug mode) will almost always be
371 useful. It is very important that the transcript include your
372 POP/IMAP server's greeting line, so I can identify it in case of
373 server problems. This transcript will not reveal your passwords,
374 which are specially masked out precisely so transcripts can be
377 <p>If you upgraded your fetchmail and something broke, you should
378 include session transcripts with -v -v of both the working and
379 failing versions. Very often, the source of the problem can
380 instantly identified by looking at the differences in protocol
383 <p>If the bug involves a core dump or hang, a gdb stack trace is
384 good to have. (Bear in mind that you can attach gdb to a running
385 but hung process by giving the process ID as a second argument.)
386 You will need to reconfigure with:</p>
389 CFLAGS=-g LDFLAGS=" " ./configure
392 <p>Then rebuild in order to generate a version that can be
395 <p>Best of all is a mail file which, when fetched, will reproduce
396 the bug under the latest (current) version.</p>
398 <p>Any bug I can reproduce will usually get fixed very quickly,
399 often within 48 hours. Bugs I can't reproduce are a crapshoot. If
400 the solution isn't obvious when I first look, it may evade me for a
401 long time (or to put it another way, fetchmail is well enough
402 tested that the easy bugs have long since been found). So if you
403 want your bug fixed rapidly, it is not just sufficient but nearly
404 <em>necessary</em> that you give me a way to reproduce it.</p>
407 <h2><a id="G4" name="G4">G4. I have this idea for a neat feature.
408 Will you add it?</a></h2>
410 <p>Probably not. Most of the feature suggestions I get are for ways
411 to set various kinds of administrative policy or add more spam
412 filtering (the most common one, which I used to get about four
413 million times a week and got <em>really</em> tired of, is for
414 tin-like kill files).</p>
416 <p>You can do spam filtering better with procmail or maildrop on
417 the server side and (if you're the server sysadmin) sendmail.cf
418 domain exclusions. You can do other policy things better with the
419 <code>mda</code> option and script wrappers around fetchmail. If
420 it's a prime-time-vs.-non-prime-time issue, ask yourself whether a
421 wrapper script called from crontab would do the job.</p>
423 <p>I'm not going to do these; fetchmail's job is transport, not
424 policy, and I refuse to change it from doing one thing well to
425 attempting many things badly. One of my objectives is to keep
426 fetchmail simple so it stays reliable.</p>
428 <p>For reasons fetchmail doesn't have other commonly-requested
429 features (such as password encryption, or multiple concurrent polls
430 from the same instance of fetchmail) see the <a
431 href="http://www.tuxedo.org/~esr/fetchmail/design-notes.html">design
434 <p>Fetchmail is a mature project, no longer in constant active
435 development. It is no longer my top project, and I am going to be
436 quite reluctant to add features that might either jeopardize its
437 stability or involve me in large amounts of coding.</p>
439 <p>All that said, if you have a feature idea that really is about a
440 transport problem that can't be handled anywhere but fetchmail, lay
441 it on me. I'm very accommodating about good ideas.</p>
444 <h2><a id="G5" name="G5">G5. I want to make fetchmail behave like
445 Outlook Express.</a></h2>
447 <p>The second-most-requested feature for fetchmail, after
448 content-based filtering, is the ability to have it remove messages
449 from a maildrop after N days, typically to be used with the
450 <code>keep</code> option as a sort of poor man's newsgroup
451 facility. Microsoft's Outlook Express supports this.</p>
453 <p>This feature won't be added either. Repeat after me: fetchmail's
454 job is transport, not policy. If you want this, write a Perl or
455 Python script, to be run from a cron job, that deletes old messages
456 off your maildrop. Send it to me and I'll put it in the contrib
460 <h2><a id="G6" name="G6">G6. Is there a mailing list for exchanging
463 <p>There is a fetchmail-friends list
464 (fetchmail-friends@lists.ccil.org) for people who want to discuss
465 fixes and improvements in fetchmail and help co-develop it. It's a
466 MailMan list, which you can sign up for at <a
467 href="http://lists.ccil.org/mailman/listinfo/fetchmail-friends">http://lists.ccil.org/mailman/listinfo/fetchmail-friends</a>.
468 There is also an announcements-only list,
469 fetchmail-announce@lists.ccil.org, which you can sign up for at <a
470 href="http://lists.ccil.org/mailman/listinfo/fetchmail-announce">http://lists.ccil.org/mailman/listinfo/fetchmail-announce</a>.</p>
473 <h2><a id="G7" name="G7">G7. So, what's this I hear about a
474 fetchmail paper?</a></h2>
476 <p>The fetchmail development was also a sociological experiment, an
477 extended test to see if my theory about the critical features of
478 the Linux development model is correct.</p>
480 <p>The experiment was a success. I wrote a paper about it titled <a
481 href="http://www.tuxedo.org/~esr/writings/cathedral.html">The
482 Cathedral and the Bazaar</a> which was first presented at Linux
483 Kongress '97 in Bavaria and very well received there. It was also
484 given at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first
485 Perl Conference, at UniForum '98, and was the basis of an invited
486 presentation at Usenix '98. The folks at Netscape tell me it helped
488 href="http://www.netscape.com/newsref/pr/newsrelease558.html">give
489 away the source for Netscape Communicator</a>.</p>
491 <p>If you're reading a non-HTML dump of this FAQ, you can find the
492 paper on the Web with a search for that title.</p>
495 <h2><a id="G8" name="G8">G8. What is the best server to use with
498 <p>The short answer: IMAP 2000 running over Unix.</p>
500 <p>Here's a longer answer:</p>
502 <p>Fetchmail will work with any POP, IMAP, ETRN, or ODMR server
503 that conforms to the relevant RFCs (and even some outright broken
504 ones like <a href="#S2">Microsoft Exchange</a> and <a
505 href="#S12">Novell GroupWise</a>). This doesn't mean it works
506 equally well with all, however. POP2 servers, and POP3 servers
507 without LAST, limit fetchmail's capabilities in various ways
508 described on the manual page.</p>
510 <p>Most modern Unixes (and effectively all Linux/*BSD systems) come
511 with POP3 support preconfigured (but beware of the horribly broken
512 POP3 server mentioned in <a href="#D2">D2</a>). An increasing
513 minority also feature IMAP (you can detect IMAP support by running
514 fetchmail in AUTO mode, or by using the `Probe for supported
515 protocols' function in the fetchmailconf utility).</p>
517 <p>If you have the option, we recommend using or installing an
518 IMAP4rev1 server; it has the best facilities for tracking message
519 `seen' states. It also recovers from interrupted connections more
520 gracefully than POP3, and enables some significant performance
521 optimizations. The new <a
522 href="ftp://ftp.cac.washington.edu/imap/imap.tar.Z">IMAP 2000</a>
523 is particularly nice, as it supports CRAM-MD5 so you don't have to
524 ship your mail password over the net en clair (fetchmail
525 autodetects this capability). Older versions had support for GSSAPI
526 giving a similar effect.</p>
528 <p>Don't be fooled by NT/Exchange propaganda. M$ Exchange is just
529 plain broken (see item <a href="#S2">S2</a>) and NT cannot handle
530 the sustained load of a high-volume remote mail server. Even
531 Microsoft itself knows better than to try this; their own Hotmail
532 service runs over Solaris! For extended discussion, see John
533 Kirch's excellent <a href="http://unix-vs-nt.org/kirch/">white
534 paper</a> on Unix vs. NT performance.</p>
536 <p>Source for a high-quality supported implementation of POP is
537 available from the <a
538 href="ftp://ftp.qualcomm.com/eudora/servers/unix/popper/">Eudora
539 FTP site</a>. Don't use 2.5, which has a rather restrictive
540 license. The 2.5.2 version appears to restore the open-source
541 license of previous versions.</p>
544 <h2><a id="G9" name="G9">G9. What is the best mail program to use
545 with fetchmail?</a></h2>
547 <p>Fetchmail will work with all popular <a href="#T1">mail
548 transport programs</a>. It also doesn't care which user agent you
549 use, and user agents are as a rule almost equally indifferent to
550 how mail is delivered into your system mailbox. So any of the
551 popular Unix mail agents -- <a
552 href="http://www.myxa.com/old/elm.html">elm</a>, <a
553 href="http://www.washington.edu/pine/">pine</a>, <a
554 href="http://www.cs.indiana.edu/docproject/mail/mh.html">mh</a>, or
555 <a href="http://www.mutt.org">mutt</a> -- will work fine with
558 <p>All this having been said, I can't resist putting in a discreet
559 plug for <a href="http://www.mutt.org">mutt</a>. My own personal
560 mail setup is sendmail plus fetchmail plus mutt. Mutt's interface
561 is only a little different from that of its now-moribund ancestor
562 elm, but its excellent handling of MIME and PGP put it in a class
563 by itself. You won't need its built-in POP3 support, though; most
564 of the mutt developers will cheerfully admit that fetchmail's is
568 <h2><a id="G10" name="G10">G10. How can I avoid sending my password
571 <p>Depending on what your mail server you are talking to, this
572 ranges from trivial to impossible. It may even be next to
575 <p>Most people use fetchmail over phone wires, which are hard to
576 tap. Anybody with the skill and resources to do this could get into
577 your server mailbox with much less effort by subverting the server
578 host. So if your provider setup is modem wires going straight into
579 a service box, you probably don't need to worry.</p>
581 <p>In general there is little point in trying to secure your
582 fetchmail transaction unless you trust the security of the server
583 host you are retrieving mail from. Your vulnerability is more
584 likely to be an insecure local network on the server end (e.g. to
585 somebody with a TCP/IP packet sniffer intercepting Ethernet traffic
586 between the modem concentrator you dial in to and the mailserver
589 <p>Having realized this, you need to ask whether password
590 encryption alone will really address your security exposure. If you
591 think you might be snooped between server and client, it's better
592 to use end-to-end encryption on your whole mail stream so none of
593 it can be read. One of the advantages of fetchmail over
594 conventional SMTP-push delivery is that you may be able to arrange
595 this by using ssh(1); see <a href="#K3">K3</a>.</p>
597 <p>Note that ssh is not a complete privacy solution either, as your
598 mail could have been snooped in transit to your POP server from
599 wherever it originated. For best security, agree with your
600 correspondents to use a tool such as <a
601 href="http://www.gnupg.org/">GPG</a> (Gnu Privacy Guard) or PGP
602 (Pretty Good Privacy).</p>
604 <p>If ssh/sshd isn't available, or you find it too complicated for
605 you to set up, password encryption will at least keep a malicious
606 cracker from deleting your mail, and require him to either tap your
607 connection continuously or crack root on the server in order to
610 <p>You can deduce what encryptions your mail server has available
611 by looking at the server greeting line (and, for IMAP, the response
612 to a CAPABILITY query). Do a <code>fetchmail -v</code> to see
613 these, or telnet direct to the server port (110 for POP3, 143 for
616 <p>If your mailserver is using IMAP 2000, you'll have CRAM-MD5
617 support built in. Fetchmail autodetects this; you can skip the rest
620 <p>The POP3 facility you are most likely to have available is APOP.
621 This is a POP3 feature supported by many servers (fetchmailconf's
622 autoprobe facility will detect it and tell you if you have it). If
623 you see something in the greeting line that looks like an
624 angle-bracket-enclosed Internet address with a numeric left-hand
625 part, that's an APOP challenge (it will vary each time you log in).
626 You can register a secret on the host (using
627 <code>popauth(8)</code> or some program like it). Specify the
628 secret as your password in your .fetchmailrc; it will be used to
629 encrypt the current challenge, and the encrypted form will be sent
630 back the the server for verification.</p>
632 <p>Alternatively, you may have Kerberos available. This may require
633 you to set up some magic files in your home directory on your
634 client machine, but means you can omit specifying any password at
637 <p>Fetchmail supports two different Kerberos schemes. One is a POP3
638 variant called KPOP; consult the documentation of your mail server
639 to see if you have it (one clue is the string "krb-IV" in the
640 greeting line on port 110). The other is an IMAP and POP3 facility
641 described by RFC1731 and RFC1734. You can tell if this one is
642 present by looking for AUTH=KERBEROS_V4 in the CAPABILITY
645 <p>If you are fetching mail from a CompuServe POP3 account, you can
646 use their RPA authentication (which works much like APOP). See <a
647 href="#S3">S3</a> for details. If you are fetching mail from
648 Microsoft Exchange using IMAP, you will be able to use NTLM.</p>
650 <p>Your POP3 server may have the RFC1938 OTP capability to use
651 one-time passwords (if it doesn't, you can get OTP patches for the
652 2.2 version of the Qualcomm popper from <a href="#cmetz">Craig
653 Metz</a>). To check this, look for the string "otp-" in the
654 greeting line. If you see it, and your fetchmail was built with
655 OPIE support compiled in (see the distribution INSTALL file),
656 fetchmail will detect it also. When using OTP, you will specify a
657 password but it will not be sent en clair.</p>
659 <p>You can get both POP3 and IMAP OTP patches from <a id="cmetz"
660 name="cmetz">Craig Metz</a> at <a
661 href="http://www.inner.net/pub/">http://www.inner.net/pub/</a>.</p>
663 <p>These patches use a SASL authentication method named "X-OTP"
664 because there is not currently a standard way to do this; fetchmail
665 also uses this method, so the two will interoperate happily. They
666 better, because this is how Craig gets his mail ;-)</p>
668 <p>Finally, you can use <a href="#K5">SSL</a> for complete
669 end-to-end encryption if you have an SSL-enabled mailserver.</p>
672 <h2><a id="G11" name="G11">G11. Is any special configuration needed
673 to use a dynamic IP address?</a></h2>
675 <p>Yes. In order to avoid giving indigestion to certain picky MTAs
676 (notably <a href="#T3">exim</a>), fetchmail always makes the RCPT
677 TO address it feeds the MTA a fully qualified one with a hostname
678 part. Normally it does this by appending @ and "localhost", but
679 when you are using Kerberos or ETRN mode it will append @ and your
680 machine's fully-qualified domain name (FQDN).</p>
682 <p>Appending the FQDN can create problems when fetchmail is running
683 in daemon mode and outlasts the dynamic IP address assignment your
684 client machine had when it started up.</p>
686 <p>Since the new IP address (looked up at RCPT TO interpretation
687 time) doesn't match the original, the most benign possible result
688 is that your MTA thinks it's seeing a relaying attempt and refuses.
689 More frequently, fetchmail will try to connect to a nonexistent
690 host address and time out. Worst case, you could up forwarding your
691 mail to the wrong machine!</p>
693 <p>Use the <code>smtpaddress</code> option to force the appended
694 hostname to one with a (fixed) IP address of 127.0.0.1 in your
695 <code>/etc/hosts</code>. (The name `localhost' will usually work;
696 or you can use the IP address itself).</p>
698 <p>Only one fetchmail option interacts directly with your IP
699 address, `<code>interface</code>'. This option can be used to set
700 the gateway device and restrict the IP address range fetchmail will
701 use. Such a restriction is sometimes useful for security reasons,
702 especially on multihomed sites. See <a href="#C3">C3</a>.</p>
704 <p>I recommend against trying to set up the <code>interface</code>
705 option when initially developing your poll configuration -- it's
706 never necessary to do this just to get a link working. Get the link
707 working first, observe the actual address range you see on
708 connections, and add an <code>interface</code> option (if you need
711 <p>You can't use ETRN if you have a dynamic IP address (your ISP
712 changes your IP address occasionally, possibly with every connect).
713 You need to have your own registered domain and a definite IP
714 address registered for that domain. The server needs to be
715 configured to accept mail for your domain but then queue it to
716 forward to your machine. ETRN just tells to server to flush its
717 queue for your domain. Fetchmail doesn't actually get the mail in
720 <p>You can use On-Demand Mail Relay (ODMR) with a dynamic IP
721 address; that's what it was designed for, and it provides
722 capabilities very similar to ETRN. Unfortunately ODMR servers are
723 not yet widely deployed, as of early 2001.</p>
725 <p>If you're using a dynamic-IP configuration, one other
726 (non-fetchmail) problem you may run into with outgoing mail is that
727 some sites will bounce your email because the hostname your giving
728 them isn't real (and doesn't match what they get doing a reverse
729 DNS on your dynamically-assigned IP address). If this happens, you
730 need to hack your sendmail so it masquerades as your host.
737 <p>in your <code>sendmail.cf</code> will work, or you can set</p>
740 MASQUERADE_AS(smarthost.here)
743 <p>in the m4 configuration and do a reconfigure. (In both cases,
744 replace <code>smarthost.here</code> with the actual name of your
745 mailhost.) See the <a
746 href="http://www.lege.com/sendmail-FAQ.txt">sendmail FAQ</a> for
750 <h2><a id="G12" name="G12">G12. Is any special configuration needed
751 to use firewalls?</a></h2>
753 <p>No. You can use fetchmail with SOCKS, the standard tool for
754 indirecting TCP/IP through a firewall. You can find out about
755 SOCKS, and download the SOCKS software including server and client
756 code, at the <a href="http://www.socks.nec.com/">SOCKS distribution
759 <p>The specific recipe for using fetchmail with a firewall is at <a
760 href="#K1">K1</a></p>
763 <h2><a id="G13" name="G13">G13. Is any special configuration needed
764 to <em>send</em> mail?</a></h2>
766 <p>A user asks: but how do we send mail out to the POP3 server? Do
767 I need to implement another tool or will fetchmail do this too?</p>
769 <p>Fetchmail only handles the receiving side. The sendmail or other
770 preinstalled MTA on your client machine will handle sending mail
771 automatically; it will ship mail that is submitted while the
772 connection is active, and put mail that is submitted while the
773 connection is inactive into the outgoing queue.</p>
775 <p>Normally, sendmail is also run periodically (every 15 minutes on
776 most Linux systems) in a mode that tries to ship all the mail in
777 the outgoing queue. If you have set up something like pppd to
778 automatically dial out when your kernel is called to open a TCP/IP
779 connection, this will ensure that the mail gets out.</p>
782 <h2><a id="G14" name="G14">G14. Is fetchmail
783 Y2K-compliant?</a></h2>
785 <p>Fetchmail is fully Y2K-compliant.</p>
787 <p>Fetchmail could theoretically have problems when the 32-bit
788 time_t counters roll over in 2038, but I doubt it. Timestamps
789 aren't used for anything but log entry generation. Anyway, if you
790 aren't running on a 64-bit machine by then, you'll deserve to
794 <h2><a id="G15" name="G15">G15. Is there a way in fetchmail to
795 support disconnected IMAP mode?</a></h2>
797 <p>No. Fetchmail is a mail transport agent, best understood as a
798 protocol gateway between POP3/IMAP servers and SMTP. Disconnected
799 operation requires an elaborate interactive client. It's a very
800 different problem.</p>
803 <h2><a id="G16" name="G16">G16. How will fetchmail perform under
804 heavy loads?</a></h2>
806 <p>Fetchmail streams message bodies line-by-line; the most core it
807 ever requires per message is enough memory to hold the RFC822
808 header, and that storage is freed when body processing begins. It
809 is, accordingly, quite economical in its use of memory.</p>
811 <p>After startup time, a fetchmail running in daemon mode stats its
812 configuration file once per poll cycle to see whether it has
813 changed and should be rescanned. Other than that, a fetchmail in
814 normal operation doesn't touch the disk at all; that job is left up
815 to the MTA or MDA the fetchmail talks to.</p>
817 <p>Fetchmail's performance is usually bottlenecked by latency on
818 the POP server or (less often) on the TCP/IP link to the server.
819 This is not a problem readily solved by tuning fetchmail, or even
820 by buying more TCP/IP capacity (which tends to improve bandwidth
821 but not necessarily latency).</p>
824 <h2><a id="B1" name="B1">B1. Make coughs and dies when building on
827 <p>The vendor-supplied make on FreeBSD systems can only be used
828 within FreeBSD's "scope", e.g. the ports collection. Type "gmake"
829 to run GNU make and better things will happen.</p>
832 <h2><a id="B2" name="B2">B2. Lex bombs out while building the
833 fetchmail lexer.</a></h2>
835 <p>In the immortal words of Alan Cox the last time this came up:
836 ``Take the Solaris lex and stick it up the backside of a passing
837 Sun salesman, then install <a
838 href="ftp://ftp.gnu.org/pub/non-gnu/flex/">flex</a> and use that.
839 All will be happier.''</p>
841 <p>I couldn't have put it better myself, and ain't going to try
844 <p>(The same problem has been reported under HP-UX v10.20 and
848 <h2><a id="B3" name="B3">B3. I get link failures when I try to
849 build fetchmail.</a></h2>
851 <p>If you get errors resembling these</p>
854 mxget.o(.text+0x35): undefined referenceto `__res_search'
855 mxget.o(.text+0x99): undefined reference to`__dn_skipname'
856 mxget.o(.text+0x11c): undefined reference to`__dn_expand'
857 mxget.o(.text+0x187): undefined reference to`__dn_expand'
858 make: *** [fetchmail] Error 1
861 <p>then you must add "-lresolv" to the LOADLIBS line in your
862 Makefile once you have installed the `bind' package.</p>
864 <p>If you get link errors involving <tt>dcgettext</tt>, like
868 rcfile_y.o: In function `yyparse':
869 rcfile_y.o(.text+0x3aa): undefined reference to `dcgettext__'
870 rcfile_y.o(.text+0x4f2): undefined reference to `dcgettext__'
871 rcfile_y.o(.text+0x5ee): undefined reference to `dcgettext__'
872 rcfile_y.o: In function `yyerror':
873 rcfile_y.o(.text+0xc7c): undefined reference to `dcgettext__'
874 rcfile_y.o(.text+0xcc8): undefined reference to `dcgettext__'
875 rcfile_y.o(.text+0xdf9): more undefined references to `dcgettext__' follow
878 <p>reconfigure with <tt>configure --with-included-gettext</tt>.
879 This is due to some brain-damage in the GNU internationalization
883 <h2><a id="B4" name="B4">B4. I get build failures in the intl
886 <p>Reconfigure with <tt>--disable-nls</tt> and recompile.</p>
888 <p>GNU gettext is an overengineered, fragile pile of crap. I have
889 teetered on the brink of removing support for it entirely several
893 <h2><a id="F1" name="F1">F1. Why does my old .fetchmailrc file no
894 longer work?</a></h2>
896 <h3>If your file predates 5.8.9</h3>
898 <p>If you were using ETRN mode, change your <tt>smtphost</tt>
899 option to a <tt>fetchdomains</tt> option.</p>
901 <h3>If your file predates 5.8.3</h3>
903 <p>The `via localhost' special case for use with ssh tunnelling is
904 gone. Use the %h feature of <tt>plugin</tt> instead.</p>
906 <h3>If your file predates 5.6.8</h3>
908 <p>In 5.6.8, the <tt>preauth</tt> keyword and option were changed
909 back to <tt>auth</tt>. The <tt>preauth</tt> synonym will still be
910 supported through a few more point releases.</p>
912 <h3>If your file predates 5.6.5</h3>
914 <p>The <tt>imap-gss</tt>, <tt>imap-k4</tt>, and <tt>imap-login</tt>
915 protocol types are gone. This is a result of a major re-factoring
916 of the authentication machinery; fetchmail can now use Kerberos V4
917 and GSSAPI not just with IMAP but with POP3 servers that have
918 RFC1734 support for the AUTH command.</p>
920 <p>When trying to identify you to an IMAP or POP mailserver,
921 fetchmail now first tries methods that don't require a password
922 (GSSAPI, KERBEROS_IV); then it looks for methods that mask your
923 password (CRAM-MD5, X-OTP); and only if it the server doesn't
924 support any of those will it ship your password en clair.</p>
926 <p>Setting the <tt>preauth</tt> option to any value other than
927 `password' will prevent from looking for a password in your
928 <tt>.netrc</tt> file or querying for it at startup time.</p>
930 <h3>If your file predates 5.1.0</h3>
932 <p>In 5.1.0, the <tt>auth</tt> keyword and option were changed to
933 <tt>preauth</tt>.</p>
935 <h3>If your file predates 4.5.5</h3>
937 <p>If the <code>dns</code> option is on (the default), you may need
938 to make sure that any hostname you specify (for mail hosts or for
939 an SMTP target) is a canonical fully-qualified hostname). In order
940 to avoid DNS overhead and complications, fetchmail no longer tries
941 to derive the fetchmail client machine's canonical DNS name at
944 <h3>If your file predates 4.0.6:</h3>
946 <p>Just after the `<code>via</code>' option was introduced, I
947 realized that the interactions between the `<code>via</code>',
948 `<code>aka</code>', and `<code>localdomains</code>' options were
949 out of control. Their behavior had become complex and confusing, so
950 much so that I was no longer sure I understood it myself. Users
951 were being unpleasantly surprised.</p>
953 <p>Rather than add more options or crock the code, I re-thought it.
954 The redesign simplified the code and made the options more
955 orthogonal, but may have broken some complex multidrop
958 <p>Any multidrop configurations that depended on the name just
959 after the `<code>poll</code>' or `<code>skip</code>' keyword being
960 still interpreted as a DNS name for address-matching purposes, even
961 in the presence of a `<code>via</code>' option, will break.</p>
963 <p>It is theoretically possible that other unusual configurations
964 (such as those using a non-FQDN poll name to generate Kerberos IV
965 tickets) might also break; the old behavior was sufficiently murky
966 that we can't be sure. If you think this has happened to you,
967 contact the maintainer.</p>
969 <h3>If your file predates 3.9.5:</h3>
971 <p>The `<code>remote</code>' keyword has been changed to
972 `<code>folder</code>'. If you try to use the old keyword, the
973 parser will utter a warning.</p>
975 <h3>If your file predates 3.9:</h3>
977 <p>It could be because you're using a .fetchmailrc that's written
978 in the old popclient syntax without an explicit
979 `<code>username</code>' keyword leading the first user entry
980 attached to a server entry.</p>
982 <p>This error can be triggered by having a user option such as
983 `<code>keep</code>' or `<code>fetchall</code>' before the first
984 explicit username. For example, if you write</p>
987 poll openmail protocol pop3
988 keep user "Hal DeVore" there is hdevore here
991 <p>the `<code>keep</code>' option will generate an entire user
992 entry with the default username (the name of fetchmail's invoking
995 <p>The popclient compatibility syntax was removed in 4.0. It
996 complicated the configuration file grammar and confused users.</p>
998 <h3>If your file predates 2.8:</h3>
1000 <p>The `<code>interface</code>', `<code>monitor</code>' and
1001 `<code>batchlimit</code>' options changed after 2.8.</p>
1003 <p>They used to be global options with `<code>set</code>' syntax
1004 like the batchlimit and logfile options. Now they're per-server
1005 options, like `<code>protocol</code>'.</p>
1007 <p>If you had something like</p>
1010 set interface = "sl0/10.0.2.15"
1013 <p>in your .fetchmailrc file, simply delete that line and insert
1014 `interface sl0/10.0.2.15' in the server options part of your
1015 `defaults' declaration.</p>
1017 <p>Do similarly for any `<code>monitor</code>' or
1018 `<code>batchlimit</code>' options.</p>
1021 <h2><a id="F2" name="F2">F2. The .fetchmailrc parser won't accept
1022 my all-numeric user name.</a></h2>
1024 <p>Either upgrade to a post-5.0.5 fetchmail or put string quotes
1027 <p>The configuration file parser in older fetchmail versions
1028 treated any all-numeric token as a number, which confused it when
1029 it was expecting a name. String quoting forces the token's
1032 <p>The lexical analyzer in 5.0.6 and beyond is smarter and assumes
1033 any token following "username" or "password" is a string.</p>
1036 <h2><a id="F3" name="F3">F3. The .fetchmailrc parser won't accept
1037 my host or username beginning with `no'.</a></h2>
1039 <p>See <a href="#F2">F2</a> You're caught in an unfortunate crack
1040 between the newer-style syntax for negated options (`no keep', `no
1041 rewrite' etc.) and the older style run-on syntax (`nokeep',
1042 `norewrite' etc.).</p>
1044 <p>Upgrade to a 5.0.6 or later fetchmail, or put string quotes
1045 around your token.</p>
1048 <h2><a id="F4" name="F4">F4. I'm getting a `parse error' message I
1049 don't understand.</a></h2>
1051 <p>The most common cause of mysterious parse errors is putting a
1052 server option after a user option. Check the manual page; you'll
1053 probably find that by moving one or more options closer to the
1054 `poll' keyword you can eliminate the problem.</p>
1056 <p>Yes, I know these ordering restrictions are hard to understand.
1057 Unfortunately, they're necessary in order to allow the `defaults'
1058 feature to work.</p>
1061 <h2><a id="C1" name="C1">C1. Why do I need a .fetchmailrc when
1062 running as root on my own machine?</a></h2>
1064 <p>Ian T. Zimmerman <itz@rahul.net> asked:</p>
1066 <p>On the machine where I'm the only real user, I run fetchmail as
1067 root from a cron job, like this:</p>
1070 fetchmail -u "itz" -p POP3 -s bolero.rahul.net
1073 <p>This used to work as is (with no .fetchmailrc file in root's
1074 home directory) with the last version I had (1.7 or 1.8, I don't
1075 remember). But with 2.0, it RECPs all mail to the local root user,
1076 unless I create a .fetchmailrc in root's home directory
1080 skip bolero.rahul.net proto POP3
1084 <p>It won't work if the second line is just "<code>user
1085 itz</code>". This is silly.</p>
1087 <p>It seems fetchmail decides to RECP the `default local user'
1088 (i.e. the uid running fetchmail) unless there are local aliases,
1089 and the `default' aliases (itz->itz) don't count. They
1094 <p>No they shouldn't. I thought about this for a while, and I don't
1095 much like the conclusion I reached, but it's unavoidable. The
1096 problem is that fetchmail has no way to know, in general, that a
1097 local user `itz' actually exists.</p>
1099 <p>"Ah!" you say, "Why doesn't it check the password file to see if
1100 the remote name matches a local one?" Well, there are two
1103 <p>One: it's not always possible. Suppose you have an SMTP host
1104 declared that's not the machine fetchmail is running on? You
1107 <p>Two: How do you know server itz and SMTP-host itz are the same
1108 person? They might not be, and fetchmail shouldn't assume they are
1109 unless local-itz can explicitly produce credentials to prove it
1110 (that is, the server-itz password in local-itz's .fetchmailrc
1113 <p>Once you start running down possible failure modes and thinking
1114 about ways to tinker with the mapping rules, you'll quickly find
1115 that all the alternatives to the present default are worse or
1116 unacceptably more complicated or both.</p>
1119 <h2><a id="C2" name="C2">C2. How can I arrange for a fetchmail
1120 daemon to get killed when I log out?</a></h2>
1122 <p>The easiest way to dispatch fetchmail on logout (which will work
1123 reliably only if you have just one login going at any time) is to
1124 arrange for the command `fetchmail -q' to be called on logout.
1125 Under bash, you can arrange this by putting `fetchmail -q' in the
1126 file `~/.bash_logout'. Most csh variants execute `~/.logout' on
1127 logout. For other shells, consult your shell manual page.</p>
1129 <p>Automatic startup/shutdown of fetchmail is a little harder to
1130 arrange if you may have multiple login sessions going. In the
1131 contrib subdirectory of the fetchmail distribution there is some
1132 shell code you can add to your .bash_login and .bash_logout
1133 profiles that will accomplish this. Thank James Laferriere
1134 <babydr@nwrain.net> for it.</p>
1136 <p>Some people start up and shut down fetchmail using the ppp-up
1137 and ppp-down scripts of pppd.</p>
1140 <h2><a id="C3" name="C3">C3. How do I know what interface and
1141 address to use with --interface?</a></h2>
1143 <p>This depends a lot on your local networking configuration (and
1144 right now you can't use it at all except under Linux and the newer
1145 BSDs). However, here are some important rules of thumb that can
1146 help. If they don't work, ask your local sysop or your Internet
1149 <p>First, you may not need to use --interface at all. If your
1150 machine only ever does SLIP or PPP to one provider, it's almost
1151 certainly by a point to point modem connection to your provider's
1152 local subnet that's pretty secure against snooping (unless someone
1153 can tap your phone or the provider's local subnet!). Under these
1154 circumstances, specifying an interface address is fairly
1157 <p>What the option is really for is sites that use more than one
1158 provider. Under these circumstances, typically one of your provider
1159 IP addresses is your mailserver (reachable fairly securely via the
1160 modem and provider's subnet) but the others might ship your packets
1161 (including your password) over unknown portions of the general
1162 Internet that could be vulnerable to snooping. What you'll use
1163 --interface for is to make sure your password only goes over the
1164 one secure link.</p>
1166 <p>To determine the device:</p>
1169 <li>If you're using a SLIP link, the correct device is probably
1172 <li>If you're using a PPP link, the correct device is probably
1175 <li>If you're using a direct connection over a local network such
1176 as an ethernet, use the command `netstat -r' to look at your
1177 routing table. Try to match your mailserver name to a destination
1178 entry; if you don't see it in the first column, use the `default'
1179 entry. The device name will be in the rightmost column.</li>
1182 <p>To determine the address and netmask:</p>
1185 <li>If you're talking to slirp, the correct address is probably
1186 10.0.2.15, with no netmask specified. (It's possible to configure
1187 slirp to present other addresses, but that's the default.)</li>
1189 <li>If you have a static IP address, run `ifconfig <device>',
1190 where <device> is whichever one you've determined. Use the IP
1191 address given after "inet addr:". That is the IP address for your
1192 end of the link, and is what you need. You won't need to specify a
1195 <li>If you have a dynamic IP address, your connection IP will vary
1196 randomly over some given range (that is, some number of the least
1197 significant bits change from connection to connection). You need to
1198 declare an address with the variable bits zero and a complementary
1199 netmask that sets the range.</li>
1202 <p>To illustrate the rule for dynamic IP addresses, let's suppose
1203 you're hooked up via SLIP and your IP provider tells you that the
1204 dynamic address pool is 255 addresses ranging from 205.164.136.1 to
1205 205.164.136.255. Then</p>
1208 interface "sl0/205.164.136.0/255.255.255.0"
1211 <p>would work. To range over any value of the last two octets
1212 (65536 addresses) you would use</p>
1215 interface "sl0/205.164.0.0/255.255.0.0"
1219 <h2><a id="C4" name="C4">C4. How can I set up support for
1220 sendmail's anti-spam features?</a></h2>
1222 <p>This answer covers versions of sendmail from 8.9.3-20 (the
1223 version installed in Red Hat 6.2) upwards. If you have an older
1224 version, upgrade to sendmail 8.9.</p>
1226 <p>Stock sendmails can now do anti-spam exclusions based on a
1227 database of filter rules. The human-readable form of the database
1228 is at <tt>/etc/mail/access</tt>. The database itself is at
1229 <tt>/etc/mail/access.db</tt>.</p>
1231 <p>The table itself uses email addresses, domain names, and network
1232 numbers as keys. For example,</p>
1235 spammer@aol.com REJECT
1236 cyberspammer.com REJECT
1240 <p>would refuse mail from spammer@aol.com, any user from
1241 cyberspammer.com (or any host within the cyberspammer.com domain),
1242 and any host on the 192.168.212.* network. (This feature can be
1243 used to do other things as well; see the <a
1244 href="http://www.sendmail.org/m4/anti-spam.html">sendmail
1245 documentation</a> for details)</p>
1247 <p>To actually set up the database, run</p>
1250 makemap hash deny <deny
1253 <p>in /etc/mail.</p>
1255 <p>To test, send a message to your mailing address from that host
1256 and then pop off the message with fetchmail, using the -v argument.
1257 You can monitor the SMTP transaction, and when the FROM address is
1258 parsed, if sendmail sees that it is an address in spamlist,
1259 fetchmail will flush and delete it.</p>
1261 <p>Under no circumstances put your <strong>mailhost</strong> or
1262 <strong>any host you accept mail from</strong> using fetchmail into
1263 your reject file. You <strong>will</strong> lose mail if you do
1267 <h2><a id="C5" name="C5">C5. How can I poll some of my mailboxes
1268 more/less often than others?</a></h2>
1270 <p>Use the <cite>interval</cite> keyword on the ones that should be
1271 checked less often. For example, if you do a poll every 5 minutes,
1272 and want to poll some mailboxes every 5 minutes and some every 30
1273 minutes, use something like this:</p>
1276 poll mainsite.example.com proto pop3 user ....
1277 poll secondary.example.com proto pop3 interval 6 user ...
1280 <p>Then secondary.example.com will be polled every 6th time that
1281 mainsite.example.com is polled, which with a polling interval of
1282 every 5 minutes means that secondary.example.com will be polled
1283 every 30 minutes.</p>
1286 <h2><a id="C6" name="C6">Fetchmail works OK started up manually,
1287 but not from an init script.</a></h2>
1289 <p>Often, startup scripts have a different environment than an
1290 interactive login shell. For instance, $HOME might point to "/root"
1291 when you are logged in as root, but it might be either unset, or
1292 set to "/" when the startup scripts are running. That means
1293 fetchmail at startup can't find the .fetchmailrc.</p>
1295 <p>Pick a location (such as /etc/fetchmailrc) and use fetchmail's
1296 -f option to point fetchmail at it. That should solve the
1300 <h2><a id="C7" name="C7">C7. How can I forward mail to another
1303 <p>To forward mail to a host other than the one you are running
1304 fetchmail on, use the <code>smtphost</code> or
1305 <code>smtpname</code> option. See the manual page for details.</p>
1308 <h2><a id="T1" name="T1">T1. How can I use fetchmail with
1311 <p>For most sendmails, no special configuration is required. Eric
1312 Allman tells me that if <code>FEATURE(always_add_domain)</code> is
1313 included in sendmail's configuration, you can leave the
1314 <code>rewrite</code> option off.</p>
1316 <p>If your sendmail complains ``sendmail does not relay'', make
1317 sure your sendmail.cf file says <code>Cwlocalhost</code> so that
1318 sendmail recognizes `localhost' as a name of its host.</p>
1320 <p>If you're mailing from another machine on your local network,
1321 also ensure that its IP address is listed in ip_allow or name in
1322 name_allow (usually in /etc/mail/)</p>
1324 <p>If you find that your sendmail doesn't like the address
1325 `FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail that
1326 fetchmail generates), you may have to set
1327 <code>FEATURE(accept_unqualified_senders)</code>.</p>
1329 <p>Günther Leber reports that Digital Unix sendmails won't
1330 work with fetchmail. The symptom is an error message "<code>553
1331 Local configuration error, hostname not recognized as
1332 local</code>". The problem is that fetchmail normally feeds
1333 sendmail with the client machine's host address in the MAIL FROM
1334 line. These sendmails think this means they're seeing the result of
1335 a mail loop and suppress the mail. You may be able to work around
1336 this by running in <code>--invisible</code> mode.</p>
1338 <p>If you want to support multidrop mode, and you can get access to
1339 your mailserver's sendmail.cf file, it's a good idea to add this
1343 H?l?Delivered-To: $h
1346 <p>This will cause the mailserver's sendmail to reliably write the
1347 appropriate envelope address into each message before fetchmail
1348 sees it, and tell fetchmail which header it is.  With this
1349 change, multidrop mode should work reliably even when the Received
1350 header omits the envelope address (which will typically be the case
1351 when the message has multiple recipients).  However it will
1352 still not distinguish the recipients, your only advantage is that
1353 no bounce will be sent if a message is BCC addressed to multiple
1354 users at your site.  To fix even that problem, you might want
1355 to try the following hack, which is however untested and quite
1359 H?J?Delivered-To: $u
1361 Mmdrop, P=/usr/bin/procmail, F=lsDFMqSPfhnu9J,
1362 S=EnvFromSMTP/HdrFromSMTP, R=EnvToSMTP/HdrToSMTP,
1363 T=DNS/RFC822/X-Unix,
1364 A=procmail -Y -a $u -d $h
1367 <p>For both hacks, you have to declare `<code>envelope
1368 "Delivered-To:"</code>' on the fetchmail side, to put the virtual
1369 domain (e.g. `domain.com') with RELAY permission into your access
1370 file and to add a line reading `<code>domain.com
1371 local:local-pop-user</code>' for the first and `<code>domain.com
1372 mdrop:local-pop-user</code>' for the second hack to your
1375 <p>You will notice that if the mail already has a Delivered-To
1376 header, sendmail will not add another.  Further, editing
1377 sendmail.cf directly is not very comfortable.  Solutions for
1378 both problems can be found in Peter `Rattacresh' Backes' `hybrid'
1379 patch against sendmail.  Have a look at it, you can find it in
1380 the contrib subdirectory.</p>
1382 <p>Feel free to try Martijn Lievaart's detailed recipe in the
1383 contrib subdirectory of the fetchmail source distribution, it
1384 attempts to realize multidrop mailboxes with an external
1387 <p>If for some reason you are invoking sendmail via the
1388 <tt>mda</tt> option (rather than delivering to port 25 via smtp),
1389 don't forget to include the -i switch. Otherwise you will
1390 occasionally get mysterious delivery failures with a SIGPIPE as the
1391 sendmail instance dies. The problem is messages with a single dot
1392 at start of a text line.</p>
1395 <h2><a id="T2" name="T2">T2. How can I use fetchmail with
1398 <p>Turn on the <code>forcecr</code> option; qmail's listener mode
1399 doesn't like header or message lines terminated with bare
1402 <p>(This information is thanks to Robert de Bath
1403 <robert@mayday.cix.co.uk>.)</p>
1405 <p>If a mailhost is using the qmail package (see <a
1406 href="http://pobox.com/~djb/qmail.html">http://pobox.com/~djb/qmail.html</a>)
1407 then, providing the local hosts are also using qmail, it is
1408 possible to set up one fetchmail link to be reliably collect the
1409 mail for an entire domain.</p>
1411 <p>One of the basic features of qmail is the `Delivered-To:'
1412 message header. Whenever qmail delivers a message to a local
1413 mailbox it puts the username and hostname of the envelope recipient
1414 on this line. The major reason for this is to prevent mail
1417 <p>To set up qmail to batch mail for a disconnected site the
1418 ISP-mailhost will have normally put that site in its `virtualhosts'
1419 control file so it will add a prefix to all mail addresses for this
1420 site. This results in mail sent to
1421 'username@userhost.userdom.dom.com' having a 'Delivered-To:' line
1425 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
1428 <p>A single host maildrop will be slightly simpler:</p>
1431 Delivered-To: mbox-userstr-username@userhost.dom.com
1434 <p>The ISP can make the 'mbox-userstr-' prefix anything they choose
1435 but a string matching the user host name is likely.</p>
1437 <p>To use this line you must:</p>
1440 <li>Ensure the option `envelope Delivered-To:' is in the fetchmail
1443 <li>Ensure you have a localdomains containing 'userdom.dom.com' or
1444 `userhost.dom.com' respectively.</li>
1447 <p>So far this reliably delivers messages to the correct machine of
1448 the local network, to deliver to the correct user the
1449 'mbox-userstr-' prefix must be stripped off of the user name. This
1450 can be done by setting up an alias within the qmail MTA on each
1451 local machine. Simply create a dot-qmail file called
1452 '.qmail-mbox-userstr-default' in the alias directory (normally
1453 /var/qmail/alias) with the contents:</p>
1456 | ../bin/qmail-inject -a -f"$SENDER" "${LOCAL#mbox-userstr-}@$HOST"
1459 <p>Note this <em>does</em> require a modern /bin/sh.</p>
1461 <p>Peter Wilson adds:</p>
1463 <p>``My ISP uses "alias-unzzippedcom-" as the prefix, which means
1464 that I need to name my file ".qmail-unzzippedcom-default". This is
1465 due to qmail's assumption that a message sent to user-xyz is
1466 handled by the file ~user/.qmail-xyz (or
1467 ~user/.qmail-default).''</p>
1469 <p>Luca Olivetti adds:</p>
1471 <p>If you aren't using qmail locally, or you don't want to set up
1472 the alias mechanism described above, you can use the option
1473 `<code>qvirtual "mbox-userstr-"</code>' in your fetchmail config
1474 file to strip the prefix from the local user name.</p>
1477 <h2><a id="T3" name="T3">T3. How can I use fetchmail with
1480 <p>If you have <code>rewrite</code> on:</p>
1482 <p>There is an RFC1123 requirement that MAIL FROM and RCPT TO
1483 addresses you pass to it have to be canonical (e.g. with a fully
1484 qualified hostname part). Therefore fetchmail tries to pass fully
1485 qualified RCPT TO addresses. But exim does not by default accept
1486 `localhost' as a fully qualified domain. This can be fixed.</p>
1488 <p>In exim.conf, add `localhost' to your local_domains declaration
1489 if it's not already present. For example, the author's site at
1490 thyrsus.com would have a line reading:</p>
1493 local_domains = thyrsus.com:localhost
1496 <p>If you have <code>rewrite</code> off:</p>
1498 <p>MAIL FROM is a potential problem if the MTAs upstream from your
1499 fetchmail don't necessarily pass canonicalized From and Return-Path
1500 addresses, and fetchmail's <code>rewrite</code> option is off. The
1501 specific case where this has come up involves bounce messages
1502 generated by sendmail on your mailer host, which have the
1503 (un-canonicalized) origin address MAILER-DAEMON.</p>
1505 <p>The right way to fix this is to enable the <code>rewrite</code>
1506 option and have fetchmail canonicalize From and Return-Path
1507 addresses with the mailserver hostname before exim sees them. This
1508 option is enabled by default, so it won't be off unless you turned
1511 <p>If you must run with <code>rewrite</code> off, there is a switch
1512 in exim's configuration files that allows it to accept domainless
1513 MAIL FROM addresses; you will have to flip it by putting the
1517 sender_unqualified_hosts = localhost
1520 <p>in the main section of the exim configuration file. Note that
1521 this will result in such messages having an incorrect domain name
1522 attached to their return address (your SMTP listener's hostname
1523 rather than that of the remote mail server).</p>
1526 <h2><a id="T4" name="T4">T4. How can I use fetchmail with
1529 <p>Smail 3.2 is very nearly plug-compatible with sendmail, and may
1530 work fine out of the box.</p>
1532 <p>We have one report that when processing multiple messages from a
1533 single fetchmail session, smail sometimes delivers them in an order
1534 other than received-date order. This can be annoying because it
1535 scrambles conversational threads. This is not fetchmail's problem,
1536 it is an smail `feature' and has been reported to the maintainers
1539 <p>Very recent smail versions require an
1540 <code>-smtp_hello_verify</code> option in the smail config file.
1541 This overrides smail's check to see that the HELO address is
1542 actually that of the client machine, which is never going to be the
1543 case when fetchmail is in the picture. According to RFC1123 an SMTP
1544 listener <em>must</em> allow this mismatch, so smail's new behavior
1545 (introduced sometime between 3.2.0.90 and 3.2.0.95) is a bug.</p>
1547 <p>You may also need to say
1548 <code>-smtp_hello_broken_allow=127.0.0.1</code> in order for smail
1549 to accept the "localhost" that fetchmail normally appends to
1550 recipient addresses.</p>
1553 <h2><a id="T5" name="T5">T5. How can I use fetchmail with SCO's
1556 <p>MMDF itself is difficult to configure, but it turns out that
1557 connecting fetchmail to MMDF's SMTP channel isn't that hard. You
1559 href="http://www.aplawrence.com/Unixart/uucptofetch.html">MMDF
1560 recipe</a> that describes replacing a UUCP link with fetchmail
1564 <h2><a id="T6" name="T6">T6. How can I use fetchmail with Lotus
1567 <p>The Lotus Notes SMTP gateway tries to deduce when it should
1568 convert \n to \r\n, but its rules are not the intuitive and
1569 correct-for-RFC822 ones. Use `forcecr'.</p>
1571 <h2><a id="T7" name="T7">T7. How can I use fetchmail with Courier
1574 <p>The courier mta doesn't like RCPT addresses that look like
1575 <code>someone@localhost</code>. Work around this with an
1576 <code>smtphost</code> or <code>smtpaddress</code>.</p>
1579 <h2><a href="T8">T8. How can I use fetchmail with vbmailshield?</a></h2>
1581 <p>vbmailshield's SMTP interpreter is broken. It doesn't understand RSET.</p>
1583 <p>As a workaround, you can set batchlimit to 1 so RSET is never used.</p>
1586 <h2><a id="S1" name="S1">S1. How can I use fetchmail with
1589 <p>Qualcomm's qpopper is probably the best-of-breed among POP3
1590 servers, and is very widely deployed. Nevertheless, it has some
1591 problems which fetchmail exposes. We recommend using <a
1592 href="#G8">IMAP</a> instead if at all possible. If you must talk to
1593 qpopper, here are some problems to be aware of:</p>
1595 <h3>Problems with retrieving large messages from qpopper 2.53</h3>
1598 href="mailto:tony@atn.com.hk"><tony@atn.com.hk></a> reports
1599 that there is a bad intercation between fetchmail and qpopper 2.5.3
1600 under Red Hat Linux versions 5.0 to 5.2, kernels 2.0.34 to 2.0.35.
1601 When fetching very large messages (over 700K) from 2.5.3, fetchmail
1602 will hang with a socket error.</p>
1604 <p>This is probably not a fetchmail bug, but rather a symptom of
1605 some problem in the networking stack that qpopper's transmission
1606 pattern is tickling, as fetchpop (another Linux POP client) also
1607 displays the hang but Netscape running under Win95 does not. The
1608 problem can also be banished by <a
1609 href="http://www.eudora.com/freeware/qpop.html">upgrading to
1610 qpopper 3.0b1</a>.</p>
1612 <h3>Bad interaction with fetchmail 4.4.2 to 4.4.7</h3>
1614 <p>Versions of fetchmail from 4.4.2 through 4.4.7 had a bad
1615 interaction with Eudora qpopper versions 2.3 and later. See <a
1616 href="#X5">X5</a> for details. The solution is to upgrade your
1620 <h2><a id="S2" name="S2">S2. How can I use fetchmail with Microsoft
1623 <p>It's been reliably reported that Exchange 2000's POP3 support is
1624 so broken that it's unusable. One symptom is that messages without
1625 a terminating newline get the POP3 message termination dot emitted
1626 -- you guessed it -- right after the last character of the message,
1627 with no terminating newline added. This will hang fetchmail or any
1628 other RFC-compliant server. IMAP is alleged to work OK, though.</p>
1630 <p>Older versions of Exchange are semi-usable.</p>
1632 <p>Fetchmail using IMAP supports the proprietary NTLM mode used
1633 with M$ Exchange servers. To enable this, configure fetchmail with
1634 the --enable-NTLM option and recompile it. Specify a user option
1635 value that looks like `user@domain': the part to the left of the @
1636 will be passed as the username and the part to the right as the
1639 <p>M$ Exchange violates the POP3 and IMAP RFCs. Its LIST command
1640 does not reveal the real sizes of mail in the pop mailbox, but the
1641 sizes of the compressed versions in the exchange mail database
1642 (thanks to Arjan De Vet and Guido Van Rooij for alerting us to this
1645 <p>Fetchmail works with M$ Exchange, despite this brain damage. Two
1646 features are compromised. One is that the --limit option will not
1647 work right (it will check against compressed and not actual sizes).
1648 The other is that a too-small SIZE argument may be passed to your
1649 ESMTP listener, assuming you're using one (this should not be a
1650 problem unless the actual size of the message is above the
1651 listener's configured length limit).</p>
1653 <p>Somewhat belatedly, I've learned that there's supposed to be a
1654 registry bit that can fix this breakage:</p>
1657 HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1658 System\Pop3 Compatibility
1661 <p>This is a bitmask that controls the variations from the standard
1662 protocol. The bits defined are:</p>
1665 <dt>0x00000001:</dt>
1667 <dd>Report exact message sizes for the LIST command</dd>
1669 <dt>0x00000002:</dt>
1671 <dd>Allow arbitrary linear whitespace between commands and
1674 <dt>0x00000004:</dt>
1676 <dd>Enable the LAST command</dd>
1678 <dt>0x00000008:</dt>
1680 <dd>Allow an empty PASS command (needed for users with blank
1681 passwords, but illegal in the protocol)</dd>
1683 <dt>0x00000010:</dt>
1685 <dd>Relax the length restrictions for arguments to commands
1686 (protocol requires 40, but some user names may be longer than
1689 <dt>0x00000020:</dt>
1691 <dd>Allow spaces in the argument to the USER command.</dd>
1694 <p>There's another one that may be useful to know about:</p>
1697 KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1698 System\Pop3 Performance
1702 <dt>0x00000001:</dt>
1704 <dd>Render messages to a temporary stream instead of sending
1705 directly from the database (should always be on)</dd>
1707 <dt>0x00000002: Flag unrenderable messages (instead of just failing
1708 commands) (should only be on if you are seeing the problems
1709 reported in KB Q168109)</dt>
1711 <dt>0x00000004:</dt>
1713 <dd>Return from the QUIT command before all messages have been
1717 <p>The Microsoft pod-person who revealed this information to me
1718 admitted that he couldn't find it anywhere in their public
1721 <p>Another specific problem we have seen with Exchange servers has
1722 as its symptom a response to LOGIN that says "NO Ambiguous Alias".
1723 Grant Edwards writes:</p>
1725 <p>This means that Exchange Server is too f*&#ing stupid to
1726 figure out which mailbox belongs to you. Instead of actually
1727 keeping track of which inbox belongs to which user, it uses some
1728 half-witted, guess-o-matic heuristic to try to guess your mailbox
1729 name from your username.</p>
1731 <p>In your case it doesn't work because your username maps to more
1732 than one mailbox. For some people it doesn't work because their
1733 username maps to zero mailboxes. This is yet another inept, lame,
1734 almost criminally negligent design decision from our friends in
1737 <p>You've got several options:</p>
1740 <li>Get your administrator to configure the server so that
1741 usernames and mailbox names are the same.</li>
1743 <li>Get your administrator to add an alias that maps your username
1744 explicitly to your mailbox name.</li>
1747 <p>But, the best option involves a tactical nuclear weapon (an old
1748 ASROC will do), pissing off a lot people who live downwind from
1749 Redmond, and your choice of any Linux, NetBSD, FreeBSD, or Solaris
1752 <p>I'll provide the CD.</p>
1755 <h2><a id="S3" name="S3">S3. How can I use fetchmail with
1756 CompuServe RPA?</a></h2>
1758 <p>First, make sure your fetchmail has the RPA support compiled in.
1759 Stock fetchmail binaries (such as you might get from an RPM) don't.
1760 You can check this by looking at the output of <code>fetchmail
1761 -V</code>; if you see the string "+RPA" after the version ID you're
1762 good to go, otherwise you'll have to build your own from sources
1763 (see the INSTALL file in the source distribution for
1766 <p>Give your CompuServe pass-phrase in lower case as your password.
1767 Add `@compuserve.com' to your user ID so that it looks like `user
1768 <UserID>@compuserve.com', where <UserID> can be either
1769 your numerical userID or your E-mail nickname. An RPA-enabled
1770 fetchmail will automatically check for csi.com in the POP server's
1771 greeting line. If that's found, and your user ID ends with
1772 `@compuserve.com', it will query the server to see if it is
1773 RPA-capable, and if so do an RPA transaction rather than a
1774 plain-text password handshake.</p>
1776 <p><strong>Warning:</strong> the debug (-v -v) output of fetchmail
1777 will show your pass-phrase in Unicode!</p>
1779 <p>These two .fetchmailrc entries show the difference between an
1780 RPA and non-RPA configuration:</p>
1783 # This version will use RPA
1784 poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1785 user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
1786 is LOCAL_USER here options fetchall stripcr
1788 # This version will not use RPA
1789 poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1790 user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
1791 is LOCAL_USER here options fetchall stripcr
1795 <h2><a id="S4" name="S4">S4. How can I use fetchmail with Demon
1796 Internet's SDPS?</a></h2>
1798 <h3>Single-drop mode</h3>
1800 <p>You can get fetchmail to download the email for just one user
1801 from Demon Internet's POP3 server by giving it a username
1802 consisting of your Demon user name followed by your account name,
1803 with an at-sign between them.</p>
1805 <p>For example, to download email for the user
1806 <philh@vision25.demon.co.uk>, you could use the following
1807 .fetchmailrc file:</p>
1810 set postmaster "philh"
1811 poll pop3.demon.co.uk with protocol POP3:
1812 user "philh@vision25" is philh
1815 <h3>Multi-drop mode</h3>
1817 <p>Demon Internet's SDPS service is an implementation of POP3. All
1818 messages have a Received: header added when they enter the
1819 maildrop, like this:</p>
1822 Received: from punt-1.mail.demon.net by mailstore for fred@xyz.demon.co.uk
1823 id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT
1826 <p>To enable multi-drop mode you need to tell fetchmail that
1827 'mailstore' is the name of the host which accepted the mail, and
1828 let it know the hostname part(s) of your E-mail address. The
1829 following example assumes that your hostname is xyz.demon.co.uk,
1830 and that you have also bought "mail forwarding" for the domain
1831 my-company.co.uk (in which case your MTA must also be configured to
1832 accept mail sent to user@my-company.co.uk)</p>
1835 poll pop3.demon.co.uk proto pop3 aka mailstore no dns:
1836 localdomains xyz.demon.co.uk my-company.co.uk
1840 <p>Note that Demon may delete mail on the server which is more than
1841 30 days old; see their <a
1842 href="http://www.demon.net/helpdesk/products/mail/sdps-tech.shtm">POP3
1843 page</a> for details.</p>
1845 <h3>The SDPS extension</h3>
1847 <p>There's a different way to do multidrop. It's not necessary on
1848 Demon Internet, since fetchmail can parse Received addresses, but
1849 the person who implemented this didn't know that. It may be useful
1850 if Demon Internet ever changes mail transports.</p>
1852 <p>SDPS includes a non-standard extension for retrieving the
1853 envelope of a message (*ENV), which fetchmail optionally supports
1854 if compiled with the --enable-SDPS option. If you have it, the
1855 first line of the fetchmail -V response will include the string
1858 <p>Once you have SDPS compiled in, fetchmail in POP3 mode will
1859 automatically detect when it's talking to a Demon Internet host in
1860 multidrop mode, and use the *ENV extension to get an envelope To
1863 <p>The autodetection works by looking at the hostname in the POP3
1864 greeting line; if you're accessing Demon Internet through a proxy
1865 it may fail. To force SDPS mode, pick "sdps" as your protocol.</p>
1868 <h2><a id="S5" name="S5">S5. How can I use fetchmail with usa.net's
1871 <p>Enable `<code>fetchall</code>'. A user reports that the 2.2
1872 version of USA.NET's POP server reports that you must use the
1873 `<code>fetchall</code>' option to make sure that all of the mail is
1874 retrieved, otherwise some may be left on the server. This is almost
1875 certainly a server bug.</p>
1877 <p>The usa.net servers (at least in their 2.2 version, June 1998)
1878 don't handle the TOP command properly, either. Regardless of the
1879 argument you give it, they retrieve only about 10 lines of the
1880 message. Fetchmail normally uses TOP for message retrieval in order
1881 to avoid marking messages seen, but `<code>fetchall</code>' forces
1882 it to use RETR instead.</p>
1884 <p>Also, we're told USA.NET adds a ton of hops to your messages.
1885 You may need to raise the MaxHopCount parameter in your sendmail.cf
1886 to avoid having fetched mail rejected.</p>
1888 <p>(Note: Other failure modes have been reported on usa.net's
1889 servers. They seem to be chronically flaky. We recommend finding
1890 another provider.)</p>
1893 <h2><a id="S6" name="S6">S6. How can I use fetchmail with HP
1896 <p>No special configuration is required, but OpenMail versions
1897 prior to 6.0 have an annoying bug similar to the big one in <a
1898 href="#S2">Microsoft Exchange</a>. The message sizes it gives in
1899 the LIST are rounded to the nearest 1024 bytes. It also has a nasty
1900 habit of discarding headers it doesn't recognize, such as X- and
1901 Resent- headers.</p>
1903 <p>As with M$ Exchange, the only real fix for these problems is to
1904 get a POP (or preferably IMAP) server that isn't brain-dead.
1905 OpenMail's project manager claims these bugs have been fixed in
1908 <p>We've had a more recent report (December 2001) that the TOP
1909 command fails, returning only one line regrardless of its argument,
1910 on something identifying itself as "OpenMail POP3 interface".</p>
1913 <h2><a id="S7" name="S7">S7. How can I use fetchmail with geocities
1914 POP3 servers?</a></h2>
1916 <p>Nathan Cutler reports that the the mail.geocities.com POP3
1917 servers fail to include the first Received line of the message in
1918 the send to fetchmail. This can solve problems if your MUA
1919 interprets Received continuations as body lines and doesn't parse
1920 any of the following headers.</p>
1922 <p>Workaround is to use "mda" keyword or "-mda" switch:</p>
1925 mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d <user>"
1928 <p>Replace \t with exactly one tabulation character.</p>
1930 <p>You should also consider using "fetchall" option because
1931 Geocities' servers sometimes think that the first 45 messages have
1932 already been read.</p>
1934 <p>Fix: Get an email provider that doesn't suck. The pop-up ads on
1935 Geocities are lame, you should boycott them anyway.</p>
1938 <h2><a id="S8" name="S8">S8. How can I use fetchmail with Hotmail?</a></h2>
1940 <p>You can't, yet. But <a
1941 href="http://linux.cudeso.be/linuxdoc/gotmail.php">gotmail</a> might
1942 be what you need.</p>
1945 <h2><a id="S9" name="S9">S9. How can I use fetchmail with MSN?</a></h2>
1947 <p>You can't. MSN uses something that looks like POP3, except the
1948 authentication part is nonstandard. And of course they don't
1949 document it, so nobody but their Windows clients can speak it.</p>
1951 <p>This is a customer lock-in tactic; we recommend boycotting MSN
1952 as the only appropriate response.</p>
1954 <p>As of 5.0.8, we have support for the client side of NTLM
1955 authentication. It's possible this may enable fetchmail to talk to
1956 MSN; if so, somebody should report it so this FAQ can be
1960 <h2><a id="S10" name="S10">S10. How can I use fetchmail with
1963 <p>The SpryNet POP3 servers mark a message queried with TOP as
1964 seen. This means that if your connection drops in mid-message, it
1965 may end up invisibly stuck on your mail spool. Use the
1966 <code>fetchall</code> flag to ensure that it's recovered on the
1970 <h2><a id="S11" name="S11">S11. How can I use fetchmail with
1973 <p>The FTGate V2 server (and possibly older versions as well) has a
1974 weird bug. It answers OK twice to a TOP request! Use the
1975 <code>fetchall</code> option to force use of RETR and work around
1979 <h2><a id="S12" name="S12">S12. How can I use fetchmail with
1982 <p>You can't. At least not if you want to be able to see
1983 attachments. MailMax has a bug; it reports the message length with
1984 attachments but doesn't download them on TOP or RETR.</p>
1986 <p>Also, we're told that TOP sometimes fails to retrieve the entire
1987 message even when enough lines have been specified. The MailMax
1988 developers have acknowledged this bug as of 4 May 2000, but there
1989 is no fix yet. If you must use this server, force RETR with the
1990 <tt>fetchall</tt> option.</p>
1993 <h2><a id="S13" name="S13">S13. How can I use fetchmail with Novell
1996 <p>The Novell GroupWise IMAP server would be better named
1997 GroupFoolish; it is (according to the designer of IMAP) unusably
1998 broken. Among other things, it doesn't include a required content
1999 length in its BODY[TEXT] response.</p>
2001 <p>Fetchmail works around this problem, but we strongly recommend
2002 voting with your dollars for a server that isn't brain-dead. If you
2003 stick with code as shoddy as GroupWise seems to be, you will
2004 probably pay for it with other problems.</p>
2007 <h2><a id="S14" name="S14">S14. How can I use fetchmail with
2008 InterChange?</a></h2>
2010 <p>You can't. At least not if you want to be able to see
2011 attachments. InterChange has a bug similar to the MailMax server;
2012 it reports the message length with attachments but doesn't download
2013 them on TOP or RETR.</p>
2015 <p>On Jan 9 2001, the people at InfiniteMail sent me mail informing
2016 me that their new 3.61.08 release of InterChange fixes this
2017 problem. I don't have any reports one way or the other yet.</p>
2019 <h2><a id="S15" name="S15">S15. How can I use fetchmail with
2022 <p>Use IMAP. The GMX StreamProxy server behaves badly on
2023 authentication failures, sending back a non-conformant error
2024 message (missing an <code>-ERR</code> tag) that confuses
2028 <h2><a id="K1" name="K1">K1. How can I use fetchmail with
2031 <p>Giuseppe Guerini added a --with-socks option that supports
2032 linking with socks library. If you specify the value of this option
2033 as ``yes'', the configure script will try to find the Rconnect
2034 library and set the makefile up to link it. You can also specify a
2035 directory containing the Rconnect library.</p>
2037 <p>Alan Schmitt has added a similar --with-socks5 option that may
2038 work better if you have a recent version of the SOCKS library.</p>
2041 <h2><a id="K2" name="K2">K2. How can I use fetchmail with IPv6 and
2044 <p>To use fetchmail with IPv6, you need a system that supports
2045 IPv6, the "Basic Socket Interface Extensions for IPv6" (RFC 2133).
2046 This currently means that you need to have a BSD/OS or NetBSD
2047 system with the NRL IPv6+IPsec software distribution or a Linux
2048 system with a 2.2 or later kernel and net-tools. It should not be
2049 hard to build fetchmail on other IPv6 implementations if you can
2050 port the inet6-apps kit.</p>
2052 <p>To use fetchmail with networking security (read: IPsec), you
2053 need a system that supports IPsec, the API described in the
2054 "Network Security API for Sockets"
2055 (draft-metz-net-security-api-01.txt), and the inet6-apps kit. This
2056 currently means that you need to have a BSD/OS or NetBSD system
2057 with the NRL IPv6+IPsec software distribution. A Linux IPsec
2058 implementation supporting this API will probably appear in the
2061 <p>The NRL IPv6+IPsec software distribution can be obtained from:
2063 href="http://web.mit.edu/network/isakmp">http://web.mit.edu/network/isakmp</a></p>
2065 <p>The inet6-apps kit can be obtained from <a
2066 href="http://ftp.ps.pl/pub/linux/IPv6/inet6-apps/">http://ftp.ps.pl/pub/linux/IPv6/inet6-apps/</a>.</p>
2068 <p>More information on using IPv6 with Linux can be obtained
2073 href="http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html">
2074 http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html</a></li>
2077 href="http://www.ipv6.inner.net/ipv6">http://www.ipv6.inner.net/ipv6</a>
2081 href="http://www.inner.net/ipv6">http://www.inner.net/ipv6</a> (via
2086 <h2><a id="K3" name="K3">K3. How can I get fetchmail to work with
2089 <p>Use the <tt>plugin</tt> option. This is dead simple with
2093 plugin "ssh %h /usr/sbin/imapd"
2096 <p>You may have to use a different absolute pathname, whatever the
2097 location of imapd on your mailserver is. This option tells
2098 fetchmail that instead of opening a connection on the server's port
2099 143 and doing standard IMAP authentication, fetchmail should ssh to
2100 the server and run imapd, using the more secure ssh authentication
2101 (as well as getting ssh's end-to-end encryption). Most IMAP daemons
2102 will detect that they've been called from the command line and
2103 assume the connection is preauthenticated.</p>
2105 <p>POP3 daemons aren't quite as smart. They won't know they are
2106 preauthenticated in this mode, so you'll actually have to ship your
2107 password. It will be under ssh encryption, though, so that
2108 shouldn't be a problem.</p>
2111 <h2><a id="K4" name="K4">K4. What do I have to do to use the
2112 IMAP-GSS protocol?</a></h2>
2114 <p>Fetchmail can use RFC1731 GSSAPI authorization to safely
2115 identify you to your IMAP server, as long as you can share Kerberos
2116 V credentials with your mail host and you have a GSSAPI-capable
2117 IMAP server. UW-IMAP (available via FTP at <a
2118 href="ftp://ftp.cac.washington.edu/mail/">ftp.cac.washington.edu</a>)
2119 is the only one I'm aware of and the one I recommend anyway for
2120 other reasons. You'll need version 4.1-FINAL or greater though, and
2121 it has to have GSS support compiled in.</p>
2123 <p>Neither UW-IMAP nor fetchmail compile in support for GSS by
2124 default, since it requires libraries from the Kerberos V
2125 distribution (available via FTP at <a
2126 href="ftp://athena-dist.mit.edu/pub/ATHENA/kerberos">athena-dist.mit.edu</a>).
2127 If you have these, compiling in GSS support is simple: add a
2128 <code>--with-gssapi=[/path/to/krb5/root]</code> option to
2129 configure. For instance, I have all of my Kerberos V libraries
2130 installed under /usr/krb5 so I run <code>configure
2131 --with-gssapi=/usr/krb5</code></p>
2133 <p>Setting up Kerberos V authentication is beyond the scope of this
2134 FAQ (you may find Jim Rome's paper <a
2135 href="http://www.ornl.gov/~jar/HowToKerb.html">How to Kerberize
2136 your site</a> helpful), but you'll at least need to add a
2137 credential for imap/[mailhost] to the keytab of the mail server
2138 (IMAP doesn't just use the host key). Then you'll need to have your
2139 credentials ready on your machine (cf. kinit).</p>
2141 <p>After that things are very simple. Set your protocol to imap-gss
2142 in your .fetchmailrc, and omit the password, since imap-gss doesn't
2143 need one. You can specify a username if you want, but this is only
2144 useful if your mailbox belongs to a username different from your
2145 Kerberos principal.</p>
2147 <p>Now you don't have to worry about your password appearing in
2148 cleartext in your .fetchmailrc, or across the network.</p>
2151 <h2><a id="K5" name="K5">K5. How can I use fetchmail with
2154 <p>You'll need to have the <a
2155 href="http://www.openssl.org/">OpenSSL</a> libraries installed.
2156 Configure with --with-ssl. If you have the OpenSSL libraries
2157 installed in the default location (/usr/local/ssl) ths will
2158 suffice. If you have them installed in a non-default location,
2159 you'll need to specify it as an argument to --with-ssl after an
2162 <p>Note that there is a known bug in the implementation of SSL_peek
2163 under OpenSSL versions 0.9.5 and older that fetchmail occasionally
2164 tripped over, causing hangs. It is recommended that you install
2167 <p>Fetchmail binaries built this way support <code>ssl</code>,
2168 <code>sslkey</code>, and <code>sslcert</code> options that control
2169 SSL encryption. You will need to have an SSL-enabled mailserver to
2170 use these options. See the manual page for details and some words
2171 of care on the limited security provided.</p>
2173 <p>If your open OpenSSL session dies with a message that complains
2174 "PRNG not seeded", update or improve your operating system. This
2175 means that the OpenSSL library on your machine has been unable to
2176 locate a source of random bits from which to seed its random-number
2177 generator; normally these come from the <tt>/dev/urandom</tt>, and
2178 this message probably means your OS doesn't have that device.</p>
2180 <p>An interactive program could seed the random number generator
2181 from keystroke timings or some other form of user input. Because
2182 fetchmail is primarily designed to run forever as a background
2183 daemon, that option is not available in this case.</p>
2185 <p>If you don't have the libraries installed, but do have the
2186 OpenSSL utility toolkit, something like this may work:</p>
2189 poll MYSERVER port 993 plugin "openssl s_client -connect %h:%p"
2190 protocol imap username MYUSERNAME password MYPASSWORD
2194 <h2><a id="R1" name="R1">R1. Fetchmail isn't working, and -v shows
2195 `SMTP connect failed' messages.</a></h2>
2197 <p>Fetchmail itself is probably working, but your SMTP port 25
2198 listener is down or inaccessible.</p>
2200 <p>The first thing to check is if you can telnet to port 25 on your
2201 smtp host (which is normally `localhost' unless you've specified an
2202 smtp option in your .fetchmailrc or on the command line) and get a
2203 greeting line from the listener. If the SMTP host is inaccessible
2204 or the listener is down, fix that first.</p>
2206 <p>In Red Hat Linux 6.9, SMTP is disabled by default. To fix this,
2207 set "DAEMON=yes" in your /etc/sysconfig/sendmail file, then restart
2208 sendmail by running "/sbin/service sendmail restart".</p>
2210 <p>If the listener seems to be up when you test with telnet, the
2211 most benign and typical problem is that the listener had a
2212 momentary seizure due to resource exhaustion while fetchmail was
2213 polling it -- process table full or some other problem that stopped
2214 the listener process from forking. If your SMTP host is not
2215 `localhost' or something else in /etc/hosts, the fetchmail glitch
2216 could also have been caused by transient nameserver failure.</p>
2218 <p>Try running fetchmail -v again; if it succeeds, you had one of
2219 these kinds of transient glitch. You can ignore these hiccups,
2220 because a future fetchmail run will get the mail through.</p>
2222 <p>If the listener tests up, but you have chronic failures trying
2223 to connect to it anyway, your problem is more serious. One way to
2224 work around chronic SMTP connect problems is to use --mda. But this
2225 only attacks the symptom; you may have a DNS or TCP routing
2226 problem. You should really try to figure out what's going on
2227 underneath before it bites you some other way.</p>
2229 <p>We have one report (from toby@eskimo.com) that you can sometimes
2230 solve such problems by doing an <code>smtp</code> declaration with
2231 an IP address that your routing table maps to something other than
2232 the loopback device (he used ppp0).</p>
2234 <p>We also have a report that this error can be caused by having an
2235 /etc/hosts file that associates your client host name with more
2236 than one IP address.</p>
2238 <p>It's also possible that your DNS configuration isn't looking at
2239 <code>/etc/hosts</code> at all. If you're using libc5, look at
2240 <code>/etc/resolv.conf</code>; it should say something like:</p>
2246 <p>so your <code>/etc/hosts</code> file is checked first. If you're
2247 running GNU libc6, check your <code>/etc/nsswitch.conf</code> file.
2248 Make sure it says something like</p>
2254 <p>again, in order to make sure <code>/etc/hosts</code> is seen
2257 <p>If you have a hostname set for your machine, and this hostname
2258 does not appear in /etc/hosts, you will be able to telnet to port
2259 25 and even send a mail with rcpt to: user@host-not-in-/etc/hosts,
2260 but fetchmail can't seem to get in touch with sendmail, no matter
2261 what you set smtpaddress to.</p>
2263 <p>We had another report from a Linux user of fetchmail 2.1 who
2264 solved his SMTP connection problem by removing the reference to
2265 -lresolv from his link line and relinking. Apparently in some older
2266 Linux distributions the libc bind library version works better.</p>
2268 <p>As of 2.2, the configure script has been hacked so the bind
2269 library is linked only if it is actually needed. So under Linux it
2270 won't be, and this particular cause should go away.</p>
2273 <h2><a id="R2" name="R2">R2. When I try to configure an MDA,
2274 fetchmail doesn't work.</a></h2>
2276 <p>(I hear this one from people who have run into the blank-line
2277 problem in <a href="#X1">X1</a>.)</p>
2279 <p>Try sending yourself test mail and retrieving it using the
2280 command-line options `<code>-k -m cat</code>'. This will dump
2281 exactly what fetchmail retrieves to standard output (plus the
2282 Received line fetchmail itself adds to the headers).</p>
2284 <p>If the dump doesn't match what shows up in your mailbox when you
2285 configure an MDA, your MDA is mangling the message. If it doesn't
2286 match what you sent, then fetchmail or something on the server is
2290 <h2><a id="R3" name="R3">R3. Fetchmail dumps core when given an
2291 invalid rc file.</a></h2>
2293 <p>This is usually reported from AIX or Ultrix, but has even been
2294 known to happen on Linuxes without a recent version of
2295 <code>flex</code> installed. The problem appears to be a result of
2296 building with an archaic version of lex.</p>
2298 <p>Workaround: fix the syntax of your .fetchmailrc file.</p>
2300 <p>Fix: build and install the latest version of <a
2301 href="ftp://prep.ai.mit.edu/~ftp/pub/gnu">flex</a> from the Free
2302 Software Foundation. An FSF <a
2303 href="http://www.gnu.ai.mit.edu/order/ftp.html">mirror site</a>
2304 will help you get it faster.</p>
2307 <h2><a id="R4" name="R4">R4. Fetchmail dumps core in -V mode, but
2308 operates normally otherwise.</a></h2>
2310 <p>We've had this reported to us under Linux using libc-5.4.17 and
2311 gcc-2.7.2. It does not occur with libc-5.3.12 or earlier
2314 <p>Workaround: link with GNU malloc rather than the stock C library
2317 <p>We're told there is some problem with the malloc() code in that
2318 version which makes it fragile in the presence of multiple free()
2319 calls on the same pointer (the malloc arena gets corrupted).
2320 Unfortunately it appears from doing gdb traces that whatever free()
2321 calls producing the problem are being made by the C library itself,
2322 not the fetchmail code (they're all from within fclose, and not an
2323 fclose called directly by fetchmail, either).</p>
2326 <h2><a id="R5" name="R5">R5. Running fetchmail in daemon mode
2327 doesn't work.</a><br/>
2330 <p>We have one report from a SunOS 4.1.4 user that trying to run
2331 fetchmail in detached daemon mode doesn't work, but that using the
2332 same options with -N (nodetach) is OK. We have another report of
2333 similar behavior from one Linux user, but many other Linux users
2334 reportt no problem.</p>
2336 <p>If this happens, you have a specific portability problem with
2337 the code in daemon.c that detaches and backgrounds the daemon
2338 fetchmail. The isolated Linux case has been chased down to a
2339 failure in dup(2) that may reflect a glibc bug.</p>
2341 <p>As a workaround, you can start fetchmail with -N and an
2342 ampersand to background it. A Sun user recommends this:</p>
2345 (fetchmail --nodetach <other params> &)
2348 <p>The extra pair of parens is significant --- it makes sure that
2349 the process detaches from the initial shell (one more shell is
2350 started and dies immediately, detaching fetchmail and making it
2351 child of PID 1). This is important when you start fetchmail
2352 interactively and than quit interactive shell. The line above makes
2353 sure fetchmail lives after that!</p>
2356 <h2><a id="R6" name="R6">R6. Fetchmail randomly dies with socket
2359 <p>Check the MTU value in your PPP interface reported by
2360 <code>/sbin/ifconfig</code>. If it's over 600, change it in your
2361 PPP options file. (<code>/etc/ppp/options</code> on my box). Here
2362 are option values that work:</p>
2369 <p>Another circumstance that can trigger this is if you are polling
2370 a virtual-mail-server name that is round-robin connected to
2371 different actual servers, so you get different IP addresses on
2372 different poll cycles. To work around this, change the poll name
2373 either to the real name of one of the servers in the ring or to a
2374 corresponding IP address.</p>
2377 <h2><a id="R7" name="R7">R7. Fetchmail running as root stopped
2378 working after an OS upgrade</a></h2>
2380 <p>In RH 6.0, the HOME value in the boot-time root environment
2381 changed from /root to / as the result of a change in init. Move
2382 your .fetchmailrc or use a -f option to explicitly point at the
2383 file. (Oddly, a similar problem has been reported from Debian
2387 <h2><a id="R8" name="R8">R8. Fetchmail is timing out after fetching
2388 certain messages but before deleting them</a></h2>
2390 <p>There's a TCP/IP stalling problem under Redhat 6.0 (and possibly
2391 other recent Linuxes) that can cause this symptom. Brian Boutel
2392 writes:<</p></p>
2395 <p>TCP timestamps are turned on on my Linux boxes (I assume it's
2396 now the default). This uses 12 extra bytes per segment. When the
2397 tcp connection starts, the other end agrees a MSS of 1460, and then
2398 fragments 1460 byte chunks into 1448 and 12, because is is not
2399 allowing for the timestamp.</p>
2401 <p>Then, for reasons I can't explain, it waits a long time
2402 (typically 2 minutes) after the ack is sent before sending the next
2403 (fragmented) packet. Turning off tcp timestamps avoids the
2404 fragmentation and restores normal behaviour. To do this,
2407 <p>echo 0 > /proc/sys/net/ipv4/tcp_timestamps</p>
2409 <p>I'm still unclear about the details of why this is happening. At
2410 least [now] I am now getting good performance and no queue
2415 <h2><a id="R9" name="R9">R9. Fetchmail is timing out during message
2418 <p>This is probably a general networking issue. Sending a "RETR"
2419 command will cause the server to start sending large amounts of
2420 data, which means large packets. If your networking layer has a
2421 packet-fragmentation problem, that's where you'll see it.</p>
2424 <h2><a id="R10" name="R10">R10. Fetchmail is dying with
2427 <p>This probably means you have an <code>mda</code> option. Your
2428 MDA is croaking while being passed a message. Best fix is to remove
2429 the <code>mda</code> option and pass mail to your port 25 SMTP
2432 <p>If for some reason you are invoking sendmail via the
2433 <tt>mda</tt> option (rather than delivering to port 25 via smtp),
2434 don't forget to include the -i switch. Otherwise you will
2435 occasionally get mysterious delivery failures with a SIGPIPE as the
2436 sendmail instance dies. The problem is messages with a single dot
2437 at start of a text line.</p>
2440 <h2><a id="R11" name="R11">R11. My server is hanging up or emitting
2441 errors on CAPA.</a></h2>
2443 <p>Your POP3 server is broken. You can work around this with the
2444 declaration <tt>auth password</tt> in your .fetchmailrc.</p>
2447 <h2><a id="H1" name="H1">H1. Fetchmail hangs when used with
2450 <p>Your problem may be with pppd's `demand' option. We have a
2451 report that fetchmail doesn't play well with it, but works with
2452 pppd if `demand' is turned off. We have no idea why this is.</p>
2455 <h2><a id="H2" name="H2">H2. Fetchmail hangs during the MAIL FROM
2458 <p>The symptom: 'fetchmail -v' retrieves mail fine, but appears to
2459 hang after sending the MAIL FROM command</p>
2462 SMTP> MAIL FROM: <someone@somewhere>
2465 <p>The hang is actually occuring when sendmail looks up a sender's
2466 address in DNS. The problem isn't in fetchmail but in the
2467 configuration of sendmail. You must enable the 'nodns' and
2468 'nocanonify' features of sendmail.</p>
2470 <p>Here was my fix for RedHat 7.2:</p>
2473 <li># cd /etc/mail</li>
2475 <li># cp sendmail.mc sendmail-mine.mc</li>
2477 <li>Edit sendmail-mine.mc and add lines:
2485 <li>Build a new sendmail.cf
2488 # m4 sendmail-mine.cf > /etc/sendmail.cf
2492 <li>Restart sendmail.</li>
2495 <p>For more details consult the file
2496 /usr/share/sendmail-cf/README.</p>
2499 <h2><a id="H3" name="H3">H3. Fetchmail hangs while fetching
2502 <p>The symption: 'fetchmail -v' retrieves the first few messages,
2503 but hangs returning:</p>
2506 fetchmail: SMTP< 550 5.0.0 Access denied
2507 fetchmail: SMTP> RSET
2508 fetchmail: SMTP< 250 2.0.0 Reset state
2509 .......fetchmail: flushed
2510 fetchmail: POP3> DELE 1
2511 fetchmail: POP3< +OK marked deleted
2514 <p>Check and see if you're allowing sendmail connections through
2517 <p>Adding 'sendmail : 127.0.0.1' to /etc/hosts.allow could solve
2521 <h2><a id="D1" name="D1">D1. I think I've set up fetchmail
2522 correctly, but I'm not getting any mail.</a></h2>
2524 <p>Maybe you have a .forward or alias set up that you've forgotten
2525 about. You should probably remove it.</p>
2527 <p>Or maybe you're trying to run fetchmail in multidrop mode as
2528 root without a .fetchmailrc file. This doesn't do what you think it
2529 should; see question <a href="#C1">C1</a>.</p>
2531 <p>Or you may not be connecting to the SMTP listener. Run fetchmail
2532 -v and see <a href="#R1">R1</a>.</p>
2534 <p>Or you may have your local user set incorrectly. In the
2538 user 'remoteuser' there with password '*' is 'localuser' here
2541 <p>make sure that 'localuser' does exist and can receive mail.</p>
2544 <h2><a id="D2" name="D2">D2. All my mail seems to disappear after a
2545 dropped connection.</a></h2>
2547 <p>One POP3 daemon used in the Berkeley Unix world that reports
2548 itself as POP3 version 1.004 actually throws the queue away. 1.005
2549 fixed that. If you're running this one, upgrade immediately. (It
2550 also truncates long lines at column 1024)</p>
2552 <p>Many POP servers, if an interruption occurs, will restore the
2553 whole mail queue after about 10 minutes. Others will restore it
2554 right away. If you have an interruption and don't see it right
2555 away, cross your fingers and wait ten minutes before retrying.</p>
2557 <p>Some servers (such as Microsoft's NTMail) are mis-designed to
2558 restore the entire queue, including messages you have deleted. If
2559 you have one of these and it flakes out on you a lot, try setting a
2560 small <code>--fetchlimit</code> value. This will result in more IP
2561 connects to the server, but will mean it actually executes changes
2562 to the queue more often.</p>
2564 <p>Qualcomm's qpopper, used at many BSD Unix sites, is better
2565 behaved. If its connection is dropped, it will first execute all
2566 DELE commands as though you had issued a QUIT (this is a technical
2567 violation of the POP3 RFCs, but a good idea in a world of flaky
2568 phone lines). Then it will re-queue any message that was being
2569 downloaded at hangup time. Still, qpopper may require a noticeable
2570 amount of time to do deletions and clean up its queue. (Fetchmail
2571 waits a bit before retrying in order to avoid a `lock busy'
2575 <h2><a id="D3" name="D3">D3. Mail that was being fetched when I
2576 interrupted my fetchmail seems to have been vanished.</a></h2>
2578 <p>Fetchmail only sends a delete mail request to the server when
2579 either (a) it gets a positive delivery acknowledgment from the SMTP
2580 listener, or (b) it gets one of the spam-filter errors (see the
2581 description of the <code>antispam></code> option) from the
2582 listener. No interrupt can cause it to lose mail.</p>
2584 <p>However, IMAP2bis has a design problem in that its normal fetch
2585 command marks a message `seen' as soon as the fetch command to get
2586 it is sent down. If for some reason the message isn't actually
2587 delivered (you take a line hit during the download, or your port 25
2588 listener can't find enough free disk space, or you interrupt the
2589 delivery in mid-message) that `seen' message can lurk invisibly in
2590 your server mailbox forever.</p>
2592 <p>Workaround: add the `<code>fetchall</code>' keyword to your
2595 <p>Solution: switch to an <a href="http://www.imap.org">IMAP4</a>
2599 <h2><a id="M1" name="M1">M1. I've declared local names, but all my
2600 multidrop mail is going to root anyway.</a></h2>
2602 <p>Somehow your fetchmail is never recognizing the hostname part of
2603 recipient names it parses out of To/Cc/envelope-header lines as
2604 matching the name of the mailserver machine. To check this, run
2605 fetchmail in foreground with -v -v on. You will probably see a lot
2606 of messages with the format ``line rejected, %s is not an alias of
2607 the mailserver'' or ``no address matches; forwarding to %s.''</p>
2609 <p>These errors usually indicate some kind of DNS configuration
2610 problem either on the server or your client machine.</p>
2612 <p>The easiest workaround is to add a `<code>via</code>' option (if
2613 necessary) and add enough aka declarations to cover all of your
2614 mailserver's aliases, then say `<code>no dns</code>'. This will
2615 take DNS out of the picture (though it means mail may be
2616 uncollected if it's sent to an alias of the mailserver that you
2617 don't have listed).</p>
2619 <p>It would be better to fix your DNS, however. DNS problems can
2620 hurt you in lots of ways, for example by making your machines
2621 intermittently or permanently unreachable to the rest of the
2624 <p>Occasionally these errors indicate the sort of header-parsing
2625 problem described in <a href="#M7">M7</a>.</p>
2628 <h2><a id="M2" name="M2">M2. I can't seem to get fetchmail to route
2629 to a local domain properly.</a></h2>
2631 <p>A lot of people want to use fetchmail as a poor man's
2632 internetwork mail gateway, picking up mail accumulated for a whole
2633 domain in a single server mailbox and then routing based on what's
2634 in the To/Cc/Bcc lines.</p>
2636 <p>In general, this is not really a good idea. It would be smarter
2637 to just let the mail sit in the mailserver's queue and use
2638 fetchmail's ETRN or ODMR modes to trigger SMTP sends periodically
2639 (of course, this means you have to poll more frequently than the
2640 mailserver's expiration period). If you can't arrange this, try
2641 setting up a UUCP feed.</p>
2643 <p>If neither of these alternatives is available, multidrop mode
2644 may do (though you <em>are</em> going to get hurt by some mailing
2645 list software; see the caveats under THE USE AND ABUSE OF MULTIDROP
2646 MAILBOXES on the man page). If you want to try it, the way to do it
2647 is with the `<code>localdomains</code>' option.</p>
2649 <p>In general, if you use localdomains you need to make sure of two
2652 <p><strong>1. You've actually set up your .fetchmailrc entry to
2653 invoke multidrop mode.</strong></p>
2655 <p>Many people set a `<code>localdomains</code>' list and then
2656 forget that fetchmail wants to see more than one name (or the
2657 wildcard `*') in a `<code>here</code>' list before it will do
2658 multidrop routing.</p>
2660 <p><strong>2. You may have to set `no envelope'.</strong></p>
2662 <p>Normally, multidrop mode tries to deduce an envelope address
2663 from a message before parsing the To/Cc/Bcc lines (this enables it
2664 to avoid losing to mailing list software that doesn't put a
2665 recipient address in the To lines).</p>
2667 <p>Some ways of accumulating a whole domain's messages in a single
2668 server mailbox mean it all ends up with a single envelope address
2669 that is useless for rerouting purposes. You may have to set
2670 `<code>no envelope</code>' to prevent fetchmail from being
2671 bamboozled by this.</p>
2673 <p>Check also answer <a href="#T1">T1</a> on a reliable way to do
2674 multidrop delivery if your ISP (or your mail redirection provider)
2678 <h2><a id="M3" name="M3">M3. I tried to run a mailing list using
2679 multidrop, and I have a mail loop!</a></h2>
2681 <p>This isn't fetchmail's fault. Check your mailing list. If the
2682 list expansion includes yourself or anybody else at your mailserver
2683 (that is, not on the client side) you've created a mail loop. Just
2684 chop the host part off any local addresses in the list.</p>
2686 <p>If you use sendmail, you can check the list expansion with
2687 <code>sendmail -bv</code>.</p>
2690 <h2><a id="M4" name="M4">M4. My multidrop fetchmail seems to be
2691 having DNS problems.</a></h2>
2693 <p>We have one report from a Linux user (not the same one as in <a
2694 href="#R1">R1</a>!) who solved this problem by removing the
2695 reference to -lresolv from his link line and relinking. Apparently
2696 in some older Linux distributions the libc5 bind library version
2699 <p>As of 2.2, the configure script has been hacked so the bind
2700 library is linked only if it is actually needed. So under Linux it
2701 won't be, and this problem should go away.</p>
2704 <h2><a id="M5" name="M5">M5. I'm seeing long DNS delays before each
2705 message is processed.</a></h2>
2707 <p>Use the `<code>aka</code>' option to pre-declare as many of your
2708 mailserver's DNS names as you can. When an address's host part
2709 matches an aka name, no DNS lookup needs to be done to check
2712 <p>If you're sure you've pre-declared all of your mailserver's DNS
2713 names, you can use the `<code>no dns</code>' option to prevent
2714 other hostname parts from being looked up at all.</p>
2716 <p>Sometimes delays are unavoidable. Some SMTP listeners try to
2717 call DNS on the From-address hostname as a way of checking that the
2718 address is valid.</p>
2721 <h2><a id="M6" name="M6">M6. How do I get multidrop mode to work
2722 with majordomo?</a></h2>
2724 <p>In order for sendmail to execute the command strings in the
2725 majordomo alias file, it is necessary for sendmail to think that
2726 the mail it receives via SMTP really is destined for a local user
2727 name. A normal virtual-domain setup results in delivery to the
2728 default mailbox, rather than expansion through majordomo.</p>
2730 <p>Michael <michael@bizsystems.com> gave us a recipe for
2731 dealing with this case that pairs a run control file like this:</p>
2734 poll your.pop3.server proto pop3:
2736 localdomains virtual.localdomain1.com virtual.localdomain2.com ...
2737 user yourISPusername is root * here,
2738 password yourISPpassword fetchall
2741 <p>with a hack on your local sendmail.cf like this:</p>
2744 #############################################
2745 # virtual info, local hack for ruleset 98 #
2746 #############################################
2748 # domains to treat as direct mapped local domain
2750 CVvirtual.localdomain1.com virtual.localdomain2.com ...
2751 ---------------------------
2753 -------------------------
2754 # handle virtual users
2756 R$+ <@ $=V . > $: $1 < @ $j . >
2757 R< @ > $+ < @ $=V . > $: $1 < @ $j . >
2758 R< @ > $+ $: $1
2759 R< error : $- $+ > $* $#error $@ $1 $: $2
2760 R< $+ > $+ < @ $+ > $: $>97 $1
2763 <p>This ruleset just strips virtual domain names off the addresses
2764 of incoming mail. Your sendmail must be 8.8 or newer for this to
2765 work. Michael says:</p>
2767 <blockquote>I use this scheme with 2 virtual domains and the
2768 default ISP user+domain and service about 30 mail accounts +
2769 majordomo on my inside pop3 server with fetchmail and sendmail
2773 <h2><a id="M7" name="M7">M7. Multidrop mode isn't parsing envelope
2774 addresses from my Received headers as it should.</a></h2>
2776 <p>It may happen that you're getting what appear to be well-formed
2777 sendmail Received headers, but fetchmail can't seem to extract an
2778 envelope address from them. There can be a couple of reasons for
2781 <h3>Spurious Received lines need to be skipped:</h3>
2783 <p>First, fetchmail might be looking at the wrong Received header.
2784 Normally it looks only on the first one it sees, on the theory that
2785 that one was last added and is going to be the one containing your
2786 mailserver's theory of who the message was addressed to.</p>
2788 <p>Some (unusual) mailserver configurations will generate extra
2789 Received lines which you need to skip. To arrange this, use the
2790 optional skip prefix argument of the `envelope' option; you may
2791 need to say something like `<code>envelope 1 Received</code>' or
2792 `<code>envelope 2 Received</code>'.</p>
2794 <h3>The `by' clause doesn't contain a mailserver alias:</h3>
2796 <p>When fetchmail parses a Received line that looks like</p>
2799 Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
2800 by iserv.ttns.net (8.8.5/8.8.5) with SMTP id RAA10088
2801 for <ksturgeon@fbceg.org>; Wed, 9 Sep 1998 17:01:59 -0700
2804 <p>it checks to see if `iserv.ttns.net' is a DNS alias of your
2805 mailserver before accepting `ksturgeon@fbceg.org' as an envelope
2806 address. This check might fail if your DNS were misconfigured, or
2807 if you were using `no dns' and had failed to declare iserv.ttns.net
2808 as an alias of your server.</p>
2811 <h2><a id="M8" name="M8">M8. Users are getting multiple copies of
2814 <p>It's a consequence of multidrop. What's happening is that you
2815 have N users subscribed to the same list. The list software sends N
2816 copies, not knowing they will end up in the same multidrop box.
2817 Since they are both locally addressed to all N users, fetchmail
2818 delivers N copies to each user.</p>
2820 <p>Fetchmail tries to eliminate adjacent duplicate messages in a
2821 multidrop mailbox. However, this logic depends on the message-ID
2822 being identical in both copies. It also depends on the two copies
2823 being adjacent in the server mailbox. The former is usually the
2824 case, but the latter condition sometimes fails in a
2825 timing-dependent way if the server was processing multiple incoming
2828 <p>I could eliminate this problem by keeping a list of all
2829 message-IDs received during a poll so far and dropping any message
2830 that matches a seen mail ID. The trouble is that this is an O(N**2)
2831 operation that might significantly slow down the retrieval of large
2835 <h2><a id="X1" name="X1">X1. Spurious blank lines are appearing in
2836 the headers of fetched mail.</a></h2>
2838 <p>What's probably happening is that the POP/IMAP daemon on your
2839 mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
2840 something in your delivery path (most likely an old version of the
2841 <em>deliver</em> program, which sendmail often calls to do local
2842 delivery) is failing to recognize it as a header.</p>
2844 <p>This is not fetchmail's problem. The first thing to try is
2845 installing a current version of <em>deliver</em>. If this doesn't
2846 work, try to figure out which other program in your mail path is
2847 inserting the blank line and replace that. If you can't do either
2848 of these things, pick a different MDA (such as procmail) and
2849 declare it with the `<code>mda</code>' option.</p>
2852 <h2><a id="X2" name="X2">X2. My mail client can't see a Subject
2855 <p>First, see <a href="#X1">X1</a>. This is quite probably the same
2856 problem (X-POP3-Rcpt header or something similar being inserted by
2857 the server and choked on by an old version of
2858 <em>deliver</em>).</p>
2860 <p>The O'Reilly sendmail book does warn that IDA sendmail doesn't
2861 process X- headers correctly. If this is your problem, all I can
2862 suggest is replacing IDA sendmail, because it's broken and not
2863 RFC822 conformant.</p>
2866 <h2><a id="X3" name="X3">X3. Messages containing "From" at start of
2867 line are being split.</a></h2>
2869 <p>If you know the messages aren't split in your server mailbox,
2870 then this is a problem with your POP/IMAP server, your client-side
2871 SMTP listener or your local delivery agent. Fetchmail cannot split
2874 <p>Some POP server daemons ignore Content-Length headers and split
2875 messages on From lines. We have one report that the 2.1 version of
2876 the BSD popper program (as distributed on Solaris 2.5 and
2877 elsewhere) is broken this way.</p>
2879 <p>You can test this. Declare an mda of `cat' and send yourself one
2880 piece of mail containing "From" at start of a line. If you see a
2881 split message, your POP/IMAP server is at fault. Upgrade to a more
2884 <p>Sendmail and other SMTP listeners don't split RFC822 messages
2885 either. What's probably happening is either sendmail's local
2886 delivery agent or your mail reader are not quite RFC822-conformant
2887 and are breaking messages on what it thinks are Unix-style From
2888 headers. You can figure out which by looking at your client-side
2889 mailbox with vi or more. If the message is already split in your
2890 mailbox, your local delivery agent is the problem. If it's not,
2891 your mailreader is the problem.</p>
2893 <p>If you can't replace the offending program, take a look at your
2894 sendmail.cf file. There will likely be a line something like</p>
2897 Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u
2900 <p>describing your local delivery agent. Try inserting the `E'
2901 option in the flags part (the F= string). This will make sendmail
2902 turn each dangerous start-of-line From into a >From, preventing
2903 programs further downstream from acting up.</p>
2906 <h2><a id="X4" name="X4">X4.</a><a id="generic_mangling"
2907 name="generic_mangling">My mail is being mangled in a new and
2908 different way</a></h2>
2910 <p>The first thing you need to do is pin down what program is doing
2911 the mangling. We don't like getting bug reports about fetchmail
2912 that are actually due to some other program's malfeasance, so
2913 please go through this diagnostic sequence before sending us a
2916 <p>There are five possible culprits to consider, listed here in the
2917 order they pass your mail:</p>
2920 <li>Programs upstream of your server mailbox.</li>
2922 <li>The POP or IMAP server on your mailserver host.</li>
2924 <li>The fetchmail program itself.</li>
2926 <li>Your local sendmail.</li>
2928 <li>Your LDA (local delivery agent), as called by sendmail or
2929 specified by <code>mda</code>.</li>
2932 <p>Often it happens that fetchmail itself is OK, but using it
2933 exposes pre-existing bugs in your downstream software, or your
2934 downstream software has a bad interaction with POP/IMAP. You need
2935 to pin down exactly where the message is being garbled in order to
2936 deduce what is actually going on.</p>
2938 <p>The first thing to do is send yourself a test message, and
2939 retrieve it with a .fetchmailrc entry containing the following (or
2940 by running with the equivalent command-line options):</p>
2943 mda "cat >MBOX" keep fetchall
2946 <p>This will capture what fetchmail gets from the server, except
2947 for (a) the extra Received header line fetchmail prepends, (b)
2948 header address changes due to <code>rewrite</code>, and (c) any
2949 end-of-line changes due to the <code>forcecr</code> and
2950 <code>stripcr</code> options. MBOX will in fact contain what
2951 programs downstream of fetchmail see.</p>
2953 <p>The most common causes of mangling are bugs and
2954 misconfigurations in those downstream programs. If MBOX looks
2955 unmangled, you will know that is what is going on and that it is
2956 not fetchmail's problem. Take a look at the other FAQ items in this
2957 section for possible clues about how to fix your problem.</p>
2959 <p>If MBOX looks mangled, the next thing to do is compare it with
2960 your actual server mailbox (if possible). That's why you specified
2961 <code>keep</code>, so the server copy would not be deleted. If your
2962 server mailbox looks mangled, programs upstream of your server
2963 mailbox are at fault. Unfortunately there is probably little you
2964 can do about this aside from complaining to your site postmaster,
2965 and nothing at all fetchmail can do about it!</p>
2967 <p>More likely you'll find that the server copy looks OK. In that
2968 case either the POP/IMAP server or fetchmail is doing the mangling.
2969 To determine which, you'll need to telnet to the server port and
2970 simulate a fetchmail session yourself. This is not actually hard
2971 (both POP3 and IMAP are simple, text-only, line-oriented protocols)
2972 but requires some attention to detail. You should be able to use a
2973 fetchmail -v log as a model for a session, but remember that the
2974 "*" in your LOGIN or PASS command dump has to be replaced with your
2975 actual password.</p>
2977 <p>The objective of manually simulating fetchmail is so you can see
2978 exactly what fetchmail sees. If you see a mangled message, then
2979 your server is at fault, and you probably need to complain to your
2980 mailserver administrators. However, we like to know what the broken
2981 servers are so we can warn people away from them. So please send us
2982 a transcript of the session including the mangling <em>and the
2983 server's initial greeting line</em>. Please tell us anything else
2984 you think might be useful about the server, like the server host's
2985 operating system.</p>
2987 <p>If your manual fetchmail simulation shows an unmangled message,
2988 congratulations. You've found an actual fetchmail bug, which is a
2989 pretty rare thing these days. Complain to us and we'll fix it.
2990 Please include the session transcript of your manual fetchmail
2991 simulation along with the other things described in the FAQ entry
2992 on <a href="#G3">reporting bugs</a>.</p>
2995 <h2><a id="X5" name="X5">X5. Using POP3, retrievals seems to be
2996 fetching too much!</a></h2>
2998 <p>This may happen in versions of fetchmail after 4.4.1 and before
2999 4.4.8. Versions after 4.4.1 use POP3's TOP command rather than
3000 RETR, in order to avoid marking the message seen (leaving it unseen
3001 is helpful for later recovery if you lose your connection in the
3002 middle of a retrieval).</p>
3004 <p>Versions of fetchmail from 4.4.2 through 4.4.7 had a bad
3005 interaction with Eudora qpopper versions 2.3 and later. The TOP
3006 bounds check was fooled by an overflow condition in the TOP
3007 argument. Decrementing the TOP argument in 4.4.7 fixed this.</p>
3009 <p>Fix: Upgrade to a later version of fetchmail.</p>
3011 <p>Workaround: set the <code>fetchall</code> option. Under POP3
3012 this has the side effect of forcing RETR use.</p>
3015 <h2><a id="X6" name="X6">X6. My mail attachments are being dropped
3016 or mangled.</a></h2>
3018 <p>This isn't fetchmail's doing -- fetchmail never drops lines in
3019 message bodies or attachments. It may be your POP server, or it may
3020 be the sender's mail user agent (or a bad combination of both).</p>
3022 <p>The Mail Max POP3 server and the InterChange and Imail IMAP
3023 servers are known to simply drop MIME attachments when uploading
3024 messages. We've had sporadic reports of problems with Microsoft
3025 Exchange and Outlook servers. Windows- and NT-based POP servers
3026 seem especially prone to mangle attachments. If you are running one
3027 of these, replacing your server with a Unix machine is probably the
3028 only effective solution.</p>
3030 <p>We've also had a report that Lotus Notes sometimes trashes the
3031 MIME type of messages. In particular, it seems to modify MIME
3032 headers introducing type application/pdf, mangling the type to
3033 application/octet-stream. It may corrupt other MIME types as
3036 <p>The IMAP service of Lotus Domino has a known bug in the way it
3037 generates MIME Content-type headers (observed on Lotus Domino
3038 5.0.2b). It's a subtle one that doesn't show up when Netscape
3039 Messenger and other clients use a FETCH BODY[] to grab the whole
3040 message. When fetchmail uses FETCH RFC822.HEADER and FETCH
3041 RFC822.TEXT to get first the header and then the body, Domino
3042 generates different Boundary tags for each part, .e.g. one tag is
3043 declared in the Content-type header and another is used to separate
3044 the MIME parts in the body. This doesn't work. (I have heard a
3045 rumor that this bug is scheduled to be fixed in Domino release 6;
3046 you can find a workaround at contrib/domino.)</p>
3048 <p>Another rich source of attachment problems is Microsoft Exchange
3049 and Microsoft Outlook. If you see unreadable attachments with a
3050 ContentType of "application/x-tnef", you're having this problem.
3051 The <a href="http://world.std.com/~damned/software.html">TNEF</a>
3052 utility may help.</p>
3054 <p>Rob Funk explains: Unfortunately there also remain many mail
3055 user agents that don't write correct MIME messages. One big
3056 offender is Sun MailTool attachments, which are formatted enough
3057 like MIME that some programs could get confused; these are
3058 generated by the mailtool and dtmail programs (the mail programs in
3059 Sun's OpenWindows and CDE environments).</p>
3061 <p>One solution to problems related to misformatted MIME
3062 attachments is the <a
3063 href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/">emil</a>
3065 href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/TUTORIAL.html">tutorial</a>
3066 file at that site for details on emil. It is useful for converting
3067 character sets, attachment encodings, and attachment formats. At
3068 this writing, emil does not appear to have been maintained since a
3069 patch to version 2.1.0beta9 in late 1997, but it is still
3072 <p>One good way of using emil is from within procmail. You can have
3073 procmail look for signs of problematic message formatting, and pipe
3074 those messages through emil to be fixed. emil will not always be
3075 able to fix the problem, in which case the message is
3078 <p>A possible rule to be inserted into a .procmailrc file for using
3083 * 1^1 ^Content-Type: \/X-sun[^;]*
3084 * 1^1 ^Content-Type: \/application/mac-binhex[^;]*
3085 * 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]*
3086 * 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]*
3088 LOG="Converting $MATCH
3091 | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME \
3092 | gawk '{gsub(/\r\n?/,"\n");print $0}'
3096 <p>The "1^1" in the conditions is a way of specifying to procmail
3097 that if any one of the four listed expressions is found in the
3098 message, the total condition is considered true, and the message
3099 gets passed into emil. These four subconditions check whether the
3100 message has a Sun attachment, a binhex attachment, or a uuencoded
3101 attachment; there are others that could be added to check these
3102 things better and to check other relevant conditions. The "LOG="
3103 line writes a line into the procmail log; the lone double-quote
3104 beginning the following line makes sure the log entry gets an
3105 end-of-line character. The call to gawk (GNU awk) is for fixing
3106 end-of-line conventions, since emil sometimes leaves those in the
3107 format of the originating machine; it could probably be replaced
3108 with a sed subsitution.</p>
3110 <p>The emil call itself tries to ensure that the message uses:</p>
3113 <li>BinHex encoding for any Apple Macintosh-only attachments</li>
3115 <li>Quoted-Printable encoding for text (when necessary)</li>
3117 <li>Base64 Encoding for binary attachments</li>
3119 <li>iso-8859-1 character set for text (unfortunately emil can't yet
3120 convert from windows-1252 to iso-8859-1)</li>
3122 <li>Quoted-Printable encoding for headers</li>
3124 <li>MIME attachment format</li>
3127 <p>Most of these (the primary exceptions being the character set
3128 and the Apple binary format) are as they should be for good
3129 internet interoperability.</p>
3131 <p>Some mail servers (Lotus Domino is a suspect here) mangle
3132 Sun-formatted messages, so the conversion to MIME needs to happen
3133 before such programs see the message. The ideal is to rid the world
3134 of Sun-formatted messages: don't use mailtool for sending
3135 attachments (it doesn't understand MIME anyway, and most of the
3136 world doesn't understand its attachments, so it really shouldn't be
3137 used at all), and make sure dtmail is set to use MIME rather than
3138 mailtool's format.</p>
3141 <h2><a id="X7" name="X7">X7. Some mail attachments are hanging
3144 <p>This isn't fetchmail's problem either; fetchmail doesn't know
3145 anything about mail attachments and doesn't treat them any
3146 differently from plain message data.</p>
3148 <p>The most usual cause of this problem seems to be bugs in your
3149 network transport layer's capability to handle the very large
3150 TCP/IP packets that attachments tend to turn into. You can test
3151 this theory by trying to download the offending message through a
3152 webmail account; using HTTP for the message tends to simulate
3153 large-packet stress rather well, and you will probably find that
3154 the messages that seem to be choking fetchmail will make your HTTP
3155 download speed drop to zero.</p>
3157 <p>This problem can be caused by subtle bugs in the
3158 packet-reassembly layer of your TCP/IP stack; these often don't
3159 manifest at normal packet sizes. It may also be caused by
3160 malfunctioning path-MTU discovery on the mailserver. Or, if there's
3161 a modem in the link, it may be because the attachment contains the
3162 Hayes mode escape "+++".</p>
3165 <h2><a id="X8" name="X8">X8. A spurious ) is being appended to my
3168 <p>Blame it on that rancid pile of dung and offal called Microsoft
3169 Exchange. Due to the problem described in <a href="#S2">S2</a>, the
3170 IMAP support in fetchmail cannot follow the IMAP protocol 100%.
3171 Most of the time it doesn't matter, but if you combine it with an
3172 SMTP server that behaves unusually, you'll get a spurious ) at
3175 <p>One piece of software that can trigger this is the Interchange
3176 mail server, as used by, e.g., mailandnews.com. Here's what
3179 <p>1. Someone sends mail to your account. The last line of the
3180 message contains text. So at the SMTP level, the message ends with,
3181 e.g. "blahblah\r\n.\r\n"</p>
3183 <p>2. The SMTP handler sees the final "\r\n.\r\n" and recognizes
3184 the end of the message. However, instead of doing the normal thing,
3185 which is tossing out the ".\r\n" and leaving the first '\r\n' as
3186 part of the email body, Interchange throws out the whole
3187 "\r\n.\r\n", and leaves the email body without any line terminator
3188 at the end of it. RFC821 does not forbid this, though it probably
3191 <p>3. Fetchmail, or some other IMAP client, asks for the message.
3192 IMAP returns it, but it's enclosed inside parentheses, according to
3193 the protocol. The message size in bytes is also present. Because
3194 the message doesn't end with a line terminator, the IMAP client
3202 <p>where the ')' is from IMAP.</p>
3204 <p>4. Fetchmail only deals with complete lines, and can't trust the
3205 stated message size because Microsoft Exchange fscks it up.</p>
3207 <p>5. As a result, fetchmail takes the final 'blahblah)' and puts
3208 it at the end of the message it forwards on. If you have verbosity
3209 on, you'll get a message about actual != expected.</p>
3211 <p>There is no fix for this. The nuke mentioned in <a
3212 href="#S2">S2</a> looks more tempting all the time.</p>
3215 <h2><a id="O1" name="O1">O1. The --logfile option doesn't work if
3216 the logfile doesn't exist.</a></h2>
3218 <p>This is a feature, not a bug. It's in line with normal practice
3219 for system daemons and allows you to suppress logging by removing
3220 the log, without hacking potentially fragile startup scripts. To
3221 get around it, just touch(1) the logfile before you run fetchmail
3222 (this will have no effect on the contents of the logfile if it
3223 already exists).</p>
3226 <h2><a id="O2" name="O2">O2. Every time I get a POP or IMAP message
3227 the header is dumped to all my terminal sessions.</a></h2>
3229 <p>Fetchmail uses the local sendmail to perform final delivery,
3230 which Netscape and other clients doesn't do; the announcement of
3231 new messages is done by a daemon that sendmail pokes. There should
3232 be a ``biff'' command to control this. Type</p>
3238 <p>to turn it off. If this doesn't work, try the command</p>
3244 <p>which is essentially what <code>biff -n</code> will do. If this
3245 doesn't work, comment out any reference to ``comsat'' in your
3246 /etc/inetd.conf file and restart inetd.</p>
3248 <p>In Slackware Linux distributions, the last line in /etc/profile
3261 to solve the problem system-wide.
3264 <h2><a id="O3" name="O3">O3. Does fetchmail reread its rc file
3265 every poll cycle?</a></h2>
3267 <p>No, but versions 5.2.2 and later will notice when you modify
3268 your rc file and restart, reading it.</p>
3271 <h2><a id="O4" name="O4">O4. Why do deleted messages show up again
3272 when I take a line hit while downloading?</a></h2>
3274 <p>Because you're using a POP3 other than Qualcomm qpopper, or an
3275 IMAP with a long expunge interval.</p>
3277 <p>According to the POP3 RFCs, deletes aren't actually performed
3278 until you issue the end-of-session QUIT command. Fetchmail cannot
3279 fix this, because doing it right takes cooperation from the server.
3280 There are two possible remedies:</p>
3282 <p>One is to switch to qpopper (the free POP3 server from Qualcomm,
3283 the Eudora people). The qpopper software violates the POP3 RFCs by
3284 doing an expunge (removing deleted messages) on a line hangup, as
3285 well as on processing a QUIT command.</p>
3287 <p>The other (which we recommend) is to switch to <a
3288 href="http://www.imap.org">IMAP</a>. IMAP has an explicit expunge
3289 command and fetchmail normally uses it to delete messages
3290 immediately after they are downloaded.</p>
3292 <p>If you get very unlucky, you might take a line hit in the window
3293 between the delete and the expunge. If you've set a longer expunge
3294 interval, the window gets wider. This problem should correct itself
3295 the next time you complete a successful query.</p>
3298 <h2><a id="O5" name="O5">O5. Why is fetched mail being logged with
3299 my name, not the real From address?</a></h2>
3301 <p>Because logging is done based on the address indicated by the
3302 sending SMTP's MAIL FROM, and some listeners are picky about that
3305 <p>Some SMTP listeners get upset if you try to hand them a MAIL
3306 FROM address naming a different host than the originating site for
3307 your connection. This is a feature, not a bug -- it's supposed to
3308 help prevent people from forging mail with a bogus origin site.
3309 (RFC 1123 says you shouldn't do this exclusion...)</p>
3311 <p>Since the originating site of a fetchmail delivery connection is
3312 localhost, this effectively means these picky listeners will barf
3313 on any MAIL FROM address fetchmail hands them with an @ in it!</p>
3315 <p>Versions 2.1 and up try the header From address first and fall
3316 back to the calling-user ID. So if your SMTP listener isn't picky,
3317 the log will look right.</p>
3320 <h2><a id="O6" name="O6">O6. I'm seeing long sendmail delays or
3321 hangs near the start of each poll cycle.</a></h2>
3323 <p>Sendmail does a hostname lookup when it first starts up, and
3324 also each time it gets a HELO in listener mode.</p>
3326 <p>Your resolver configuration may be causing one of these lookups
3327 to fail and time out. Check <code>/etc/resolv.conf</code> and
3328 <code>/etc/hosts</code> file. Make sure your hostname and
3329 fully-qualified domain name are both in <code>/etc/hosts</code>,
3330 and that hosts is looked at before DNS is queried. You probably
3331 also want your remote mail server(s) to be in the hosts file.</p>
3333 <p>You can suppress the startup-time lookup if need to by
3334 reconfiguring with <code>FEATURE(nodns)</code>.</p>
3336 <p>Configuring your bind library to cache DNS lookups locally may
3337 help, and is a good idea for speeding up other services as well.
3338 Switching to a faster MTA like qmail or exim might help.</p>
3341 <h2><a id="O7" name="O7">O7. Why doesn't fetchmail deliver mail in
3342 date-sorted order?</a></h2>
3344 <p>Because that's not the order the server hands it to fetchmail
3347 <p>Fetchmail getting mail from a POP server delivers mail in the
3348 order that your server delivers mail. Fetchmail can't do anything
3349 about this; it's a limitation of the underlying POP protocol.</p>
3351 <p>In theory it might be possible for fetchmail in IMAP mode to
3352 sort messages by date, but this would be in violation of two basics
3353 of fetchmail's design philosophy: (a) to be as simple and
3354 transparent a pipe as possible, and (b) to <em>hide</em>, rather
3355 than emphasize, the differences between the remote-fetch protocols
3358 <p>Re-ordering messages is a user-agent function, anyway.</p>
3361 <h2><a id="O8" name="O8">O8. I'm using pppd. Why isn't my monitor
3362 option working?</a></h2>
3364 <p>There is a combination of circumstances that can confuse
3365 fetchmail. If you have set up demand dialing with pppd, and pppd
3366 has an idle timeout, and you have lcp-echo-interval set, then the
3367 lcp-echo-interval time must be longer than the pppd idle timeout.
3368 Otherwise it is going keep increasing the packet counters that
3369 fetchmail relies upon, triggering fetchmail into polling after its
3370 own delay interval and thus preventing the pppd link from ever
3371 reaching its inactivity timeout.</p>
3374 <h2><a id="O9" name="O9">O9. Why does fetchmail keep retrieving the
3375 same messages over and over?</a></h2>
3377 <p>First, check to see that you haven't enabled the
3378 <cite>keep</cite> and <cite>fetchall</cite> option. If you have,
3379 turn <cite>keep</cite> off.</p>
3381 <p>There are various forms of lossage involving the POP3 UIDL
3382 feature that can lead to all your old messages being seen again
3383 after a line drop. I have given up trying to fix these, as the UIDL
3384 code breaks worse every time I touch it. The problem is
3385 fundamental; maintaining and garbage-collecting the right kind of
3386 client-side state is just hard. Whoever put UIDLs in RFC1725 and
3387 removed LAST should be hung up by his thumbs and whipped with
3388 scorpions. The right answers are either (a) live with the
3389 occasional breakage, (b) switch to IMAP4, or (c) fix the code
3390 yourself and send me a patch. Unless you choose (c), I don't want
3391 to hear about it.</p>
3393 <p>This can also happen when some other mail client is logged in to
3394 your mail server, if it uses a simple exclusive-locking scheme (and
3395 many, especially most POP3 servers, do exactly that). Your
3396 fetchmail is able to retrieve the messages, but because the mailbox
3397 is write-locked by the other instance yours can neither mark
3398 messages seen or delete them. The solution is to either (a) wait
3399 for the other client to finish, or (b) terminate it.</p>
3401 <p>James Stevens <James.Stevens@kyzo.com> writes:</p>
3403 <p><em>We had a Linux box dialing the Net and collecting mail from
3404 an NT POP3 server. Fetchmail was correctly collecting and deleting
3405 each e-mail one by one. However,the dial-up connection was very
3406 unreliable and would often just drop out in the middle of a
3409 <p><em>Interestingly, unless the TCP POP3 connection was terminated
3410 normally (I guess with a POP3 "QUIT" command) NT would then roll
3411 back all the deletes !!!</em></p>
3413 <p><em>This meant if the first e-mail was very large it might just
3414 end up continuously collecting it, basically jamming the queue. Or,
3415 if the queue became very full itmight never get a long enough phone
3416 connection to retrieve the entire mailbox, and NT would roll back
3417 any deletes, so it would end up collecting (and delivering) the
3418 first few e-mails again and again. As the POP3 mailbox became
3419 fuller and fuller the chances of getting a connection long enough
3420 to collect theentire mailbox became smaller and smaller.</em></p>
3422 <p><em>Our solution was to make fetchmail only collect a few (say 5
3423 or 10) e-mails at atime, thus trying to ensure that the POP3
3424 connection is terminated correctly.</em></p>
3426 <p>Unfortunately, this is exactly the way POP3 servers are supposed
3427 to behave on a line drop, according to the RFCs. I recommend
3428 switching to IMAP and using a short expunge interval.</p>
3431 <h2><a id="O10" name="O10">O10. Why is the received date on all my
3432 messages the same?</a></h2>
3434 <p>This is a design choice in your MTA, not fetchmail. It's taking
3435 the received date from the last Received header.</p>
3438 <table width="100%" cellpadding="0" summary="Canned page footer">
3440 <td width="30%">Back to <a href="index.html">Fetchmail Home
3442 <td width="30%" align="center">To <a href="/~esr/sitemap.html">Site
3444 <td width="30%" align="right">$Date: 2002/09/04 13:58:24 $</td>
3449 <address>Eric S. Raymond <a
3450 href="mailto:esr@thyrsus.com"><esr@thyrsus.com></a></address>
3454 compile-command: "(cd ~/WWW; upload fetchmail/fetchmail-FAQ.html)"