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13 <td width="30%" align=right>$Date: 2000/12/12 03:53:25 $
16 <H1>Frequently Asked Questions About Fetchmail</H1>
18 Before reporting any bug, please read <a href="#G3">G3</a> for advice
19 on how to include diagnostic information that will get your bug fixed
20 as quickly as possible. <p>
22 If you have a question or answer you think ought to be added to this FAQ list,
23 mail it to fetchmail's maintainer, Eric S. Raymond, at
24 <A HREF="mailto:esr@thyrsus.com">esr@snark.thyrsus.com</A>.<p>
26 <h1>General questions:</h1>
28 <a href="#G1">G1. What is fetchmail and why should I bother?</a><br>
29 <a href="#G2">G2. Where do I find the latest FAQ and fetchmail sources?</a><br>
30 <a href="#G3">G3. I think I've found a bug. Will you fix it?</a><br>
31 <a href="#G4">G4. I have this idea for a neat feature. Will you add it?</a><br>
32 <a href="#G5">G5. Is there a mailing list for exchanging tips?</a><br>
33 <a href="#G6">G6. So, what's this I hear about a fetchmail paper?</a><br>
34 <a href="#G7">G7. What is the best server to use with fetchmail?</a><br>
35 <a href="#G8">G8. What is the best mail program to use with fetchmail?</a><br>
36 <a href="#G9">G9. How can I avoid sending my password en clair?</a><br>
37 <a href="#G10">G10. Is any special configuration needed to use a dynamic
39 <a href="#G11">G11. Is any special configuration needed to use firewalls?</a><br>
40 <a href="#G12">G12. Is any special configuration needed to <em>send</em> mail?</a><br>
41 <a href="#G13">G13. Is fetchmail Y2K-compliant?</a><br>
42 <a href="#G14">G14. Is there a way in fetchmail to support disconnected IMAP mode?</a><br>
43 <a href="#G15">G15. How will fetchmail perform under heavy loads?</a><br>
45 <h1>Build-time problems:</h1>
47 <a href="#B1">B1. Lex bombs out while building the fetchmail lexer.</a><br>
48 <a href="#B2">B2. I get link failures when I try to build fetchmail.</a><br>
50 <h1>Fetchmail configuration file grammar questions:</h1>
52 <a href="#F1">F1. Why does my old .fetchmailrc no longer work?</a><br>
53 <a href="#F2">F2. The .fetchmailrc parser won't accept my all-numeric user name.</a><br>
54 <a href="#F3">F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.</a><br>
55 <a href="#F4">F4. I'm getting a `parse error' message I don't understand.</a><br>
56 <a href="#F5">F5. The %h and %p escapes aren't being interporated correctly.</a><br>
58 <h1>Configuration questions:</h1>
60 <a href="#C1">C1. Why do I need a .fetchmailrc when running as root on my own machine?</a><br>
61 <a href="#C2">C2. How can I arrange for a fetchmail daemon to get killed when I log out?</a><br>
62 <a href="#C3">C3. How do I know what interface and address to use with --interface?</a><br>
63 <a href="#C4">C4. How can I set up support for sendmail's anti-spam features?</a><br>
64 <a href="#C5">C5. How can I poll some of my mailboxes more/less often than others?</a><br>
65 <a href="#C6">C6. Fetchmail works OK started up manually, but not from an init script.</a><br>
66 <a href="#C7">C7. How can I forward mail to another host?.</a><br>
68 <h1>How to make fetchmail play nice with various MTAs:</h1>
70 <a href="#T1">T1. How can I use fetchmail with sendmail?</a><br>
71 <a href="#T2">T2. How can I use fetchmail with qmail?</a><br>
72 <a href="#T3">T3. How can I use fetchmail with exim?</a><br>
73 <a href="#T4">T4. How can I use fetchmail with smail?</a><br>
74 <a href="#T5">T5. How can I use fetchmail with SCO's MMDF?</a><br>
75 <a href="#T6">T6. How can I use fetchmail with Lotus Notes?</a><br>
77 <h1>How to make fetchmail work with various servers:</h1>
79 <a href="#S1">S1. How can I use fetchmail with qpopper?</a><br>
80 <a href="#S2">S2. How can I use fetchmail with Microsoft Exchange?</a><br>
81 <a href="#S3">S3. How can I use fetchmail with Compuserve RPA?</a><br>
82 <a href="#S4">S4. How can I use fetchmail with Demon Internet's SDPS?</a><br>
83 <a href="#S5">S5. How can I use fetchmail with usa.net's servers?</a><br>
84 <a href="#S6">S6. How can I use fetchmail with HP OpenMail?</a><br>
85 <a href="#S7">S7. How can I use fetchmail with geocities POP3 servers?</a><br>
86 <a href="#S8">S8. How can I use fetchmail with Hotmail?</a><br>
87 <a href="#S9">S9. How can I use fetchmail with MSN?</a><br>
88 <a href="#S10">S10. How can I use fetchmail with SpryNet?</a><br>
89 <a href="#S11">S11. How can I use fetchmail with FTGate?</a><br>
90 <a href="#S12">S12. How can I use fetchmail with MailMax?</a><br>
91 <a href="#S13">S13. How can I use fetchmail with Novell GroupWise?</a><br>
92 <a href="#S14">S14. How can I use fetchmail with InterChange?</a><br>
94 <h1>How to set up well-known security and authentication methods:</h1>
96 <a href="#K1">K1. How can I use fetchmail with SOCKS?</a><br>
97 <a href="#K2">K2. How can I use fetchmail with IPv6 and IPsec?</a><br>
98 <a href="#K3">K3. How can I get fetchmail to work with ssh?</a><br>
99 <a href="#K4">K4. What do I have to do to use the IMAP-GSS protocol?</a><br>
100 <a href="#K5">K5. How can I use fetchmail with SSL?</a><br>
102 <h1>Runtime fatal errors:</h1>
104 <a href="#R1">R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.</a><br>
105 <a href="#R2">R2. When I try to configure an MDA, fetchmail doesn't work.</a><br>
106 <a href="#R3">R3. Fetchmail dumps core when given an invalid rc file.</a><br>
107 <a href="#R4">R4. Fetchmail dumps core in -V mode, but operates normally otherwise.</a><br>
108 <a href="#R5">R5. Running fetchmail in daemon mode doesn't work.</a><br>
109 <a href="#R6">R6. Fetchmail hangs when used with pppd.</a><br>
110 <a href="#R7">R7. Fetchmail randomly dies with socket errors.</a><br>
111 <a href="#R8">R8. Fetchmail running as root stopped working after an OS upgrade</a><br>
112 <a href="#R9">R9. Fetchmail is timing out after fetching certain
113 messages but before deleting them</a><br>
114 <a href="#R10">R10. Fetchmail is timing out during message fetches</a><br>
115 <a href="#R11">R11. Fetchmail is dying with SIGPIPE.</a><br>
117 <h1>Disappearing mail</h1>
119 <a href="#D1">D1. I think I've set up fetchmail correctly, but I'm not getting any mail.</a><br>
120 <a href="#D2">D2. All my mail seems to disappear after a dropped connection.</a><br>
121 <a href="#D3">D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.</a><br>
123 <h1>Multidrop-mode problems:</h1>
125 <a href="#M1">M1. I've declared local names, but all my multidrop mail is going to root anyway.</a><br>
126 <a href="#M2">M2. I can't seem to get fetchmail to route to a local domain properly.</a><br>
127 <a href="#M3">M3. I tried to run a mailing list using multidrop, and I have a mail loop!</a><br>
128 <a href="#M4">M4. My multidrop fetchmail seems to be having DNS problems.</a><br>
129 <a href="#M5">M5. I'm seeing long DNS delays before each message is processed.</a><br>
130 <a href="#M6">M6. How do I get multidrop mode to work with majordomo?</a><br>
131 <a href="#M7">M7. Multidrop mode isn't parsing envelope addresses from
132 my Received headers as it should.</a><br>
133 <a href="#M8">M8. Users are getting multiple copies of messages.</a><br>
135 <h1>Mangled mail:</h1>
137 <a href="#X1">X1. Spurious blank lines are appearing in the headers of fetched mail.</a><br>
138 <a href="#X2">X2. My mail client can't see a Subject line.</a><br>
139 <a href="#X3">X3. Messages containing "From" at start of line are being split.</a><br>
140 <a href="#X4">X4. My mail is being mangled in a new and different way.</a><br>
141 <a href="#X5">X5. Using POP3, retrievals seems to be fetching too much!</a><br>
142 <a href="#X6">X6. My mail attachments are being dropped or mangled.</a><br>
143 <a href="#X7">X7. Some mail attachments are hanging fetchmail.</a><br>
145 <h1>Other problems:</h1>
147 <a href="#O1">O1. The --logfile option doesn't work if the logfile doesn't exist.</a><br>
148 <a href="#O2">O2. Every time I get a POP or IMAP message the header is
149 dumped to all my terminal sessions.</a><br>
150 <a href="#O3">O3. Does fetchmail reread its rc file every poll cycle?</a><br>
151 <a href="#O4">O4. Why do deleted messages show up again when I take
152 a line hit while downloading?</a><br>
153 <a href="#O5">O5. Why is fetched mail being logged with my name, not the real From address?</a><br>
154 <a href="#O6">O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.</a><br>
155 <a href="#O7">O7. Why doesn't fetchmail deliver mail in date-sorted order?</a><br>
156 <a href="#O8">O8. I'm using pppd. Why isn't my monitor option working?</a><br>
157 <a href="#O9">O9. Why does fetchmail keep retrieving the same messages
158 over and over?</a><br>
162 <h2><a name="G1">G1. What is fetchmail and why should I bother?</a></h2>
164 Fetchmail is a one-stop solution to the remote mail retrieval problem
165 for Unix machines, quite useful to anyone with an intermittent PPP or
166 SLIP connection to a remote mailserver. It can collect mail using any
167 variant of POP or IMAP and forwards via port 25 to the local SMTP
168 listener, enabling all the normal forwarding/filtering/aliasing
169 mechanisms that would apply to local mail or mail arriving via a
170 full-time TCP/IP connection.<p>
172 Fetchmail is not a toy or a coder's learning exercise, but an
173 industrial-strength tool capable of transparently handling every
174 retrieval demand from those of a simple single-user ISP connection up
175 to mail retrieval and rerouting for an entire client domain.
176 Fetchmail is easy to configure, unobtrusive in operation, powerful,
177 feature-rich, and well documented. <P>
179 Fetchmail is <a href="http://www.opensource.org">open-source</a>
180 software. The openness of the sources is the strongest assurance of
181 quality you can have. Extensive peer review by a large,
182 multi-platform user community has shown that fetchmail is as near
183 bulletproof as the underlying protocols permit.<p>
185 Fetchmail is licensed under the <a
186 href="http://gnu.org//copyleft/gpl.html">GNU General Public
189 If you found this FAQ in the distribution, see the README for fetchmail's
190 full feature list.<p>
193 <h2><a name="G2">G2. Where do I find the latest FAQ and fetchmail
196 The latest HTML FAQ is available alongside the latest fetchmail
197 sources at the fetchmail home page:
198 <a href="http://www.tuxedo.org/~esr/fetchmail">
199 http://www.tuxedo.org/~esr/fetchmail</a>. You can also usually find
201 href="http://sunsite.unc.edu/pub/Linux/system/mail/pop/!INDEX.html">POP
202 mail tools directory on Sunsite</a>.<p>
204 A text dump of this FAQ is included in the fetchmail
205 distribution. Because it freezes at distribution release time, it may
206 not be completely current.<p>
209 <h2><a name="G3">G3. I think I've found a bug. Will you fix it?</a></h2>
211 Yes I will, provided you include enough diagnostic information for me
212 to go on. Send bugs to <a
213 href="mailto:fetchmail-friends@ccil.org">fetchmail-friends</a>. When reporting
214 bugs, please include the following:
217 <li>Your operating system.
218 <li>Your compiler version, if you built from source; otherwise, the
219 name and origin ogf the RPM or other binary package you installed.
220 <li>A copy of your POP or IMAP server's greeting line.
221 <li>The name and version of the SMTP listener or MDA you are forwarding to.
222 <li>Any command-line options you used.
223 <li>The output of fetchmail -V called with whatever other
224 command-line options you used.
227 If you have FTP access to your remote mail account, and you have any
228 suspicion that the bug was triggered by a particular message, please
229 include a copy of the message that triggered the bug.<p>
231 Often, the first thing I will do when you report a bug is tell you to
232 upgrade to the newest version of fetchmail, and then see if the
233 problem reproduces. So you'll probably save us both time if you
234 upgrade and test with the latest version <em>before</em> sending in a
237 Another useful thing you can do, if you're using POP3, is to test for
238 IMAP4 support on your mailserver using the autoprobe function of
239 fetchmailconf. If you have IMAP4, and fetchmailconf doesn't tell you
240 it's broken, switch immediately. POP3 is a weak, poorly-designed
241 protocol with chronic problems, and the later versions after RFC1725
242 actually get worse rather than better. Changing over to IMAP4 may well
243 make your problem go away -- and if your ISP doesn't have IMAP4
244 support, bug them to supply it.<p>
246 It is helpful if you include your .fetchmailrc file, but not necessary
247 unless your symptom seems to involve an error in configuration
248 parsing. If you do send in your .fetchmailrc, mask the passwords
251 If fetchmail seems to run and fetch mail, but the headers look mangled
252 (that is, headers are missing or blank lines are inserted in the
253 headers) then read the FAQ items in section <a href="#X1">X</a>
254 before submitting a bug report. Pay special attention to the item on
255 <a href="#generic_mangling">diagnosing mail mangling</a>. There are
256 lots of ways for other programs in the mail chain to screw up that
257 look like fetchmail's fault, but you may be able to fix these by
258 tweaking your configuration.<P>
260 A transcript of the failed session with -v -v (yes, that's
261 <em>two</em> -v options, enabling debug mode) will almost always be useful.
262 It is very important that the transcript include your POP/IMAP server's
263 greeting line, so I can identify it in case of server problems. This
264 transcript will not reveal your passwords, which are specially masked
265 out precisely so the transcript can be passed around.<P>
267 If the bug involves a core dump or hang, a gdb stack trace is good to have.
268 (Bear in mind that you can attach gdb to a running but hung process by
269 giving the process ID as a second argument.) You will need to
273 CFLAGS=-g LDFLAGS=" " ./configure
276 and then rebuild in order to generate a version that can be gdb-traced.<p>
278 Best of all is a mail file which, when fetched, will reproduce the
279 bug under the latest (current) version.<p>
281 Any bug I can reproduce will usually get fixed very quickly, often
282 within 48 hours. Bugs I can't reproduce are a crapshoot. If the
283 solution isn't obvious when I first look, it may evade me for a long
284 time (or to put it another way, fetchmail is well enough tested that the
285 easy bugs have long since been found). So if you want your bug fixed
286 rapidly, it is not just sufficient but nearly <em>necessary</em> that
287 you give me a way to reproduce it.<p>
290 <h2><a name="G4">G4. I have this idea for a neat feature. Will you add it?</a></h2>
292 Probably not. Most of the feature suggestions I get are for ways to
293 set various kinds of administrative policy or add more spam filtering
294 (the most common one, which I used to get about four million times a week
295 and got <em>really</em> tired of, is for tin-like kill files).<p>
297 You can do spam filtering better with procmail or maildrop on the
298 server side and (if you're the server sysadmin) sendmail.cf domain
299 exclusions. You can do other policy things better with the
300 <CODE>mda</CODE> option and script wrappers around fetchmail. If
301 it's a prime-time-vs.-non-prime-time issue, ask yourself whether a
302 wrapper script called from crontab would do the job.<p>
304 I'm not going to do these; fetchmail's job is transport, not policy, and I
305 refuse to change it from doing one thing well to attempting many things badly.
306 One of my objectives is to keep fetchmail simple so it stays reliable.<p>
308 For reasons fetchmail doesn't have other commonly-requested features
309 (such as password encryption, or multiple concurrent polls from the
310 same instance of fetchmail) see the <a
311 href="http://www.tuxedo.org/~esr/fetchmail/design-notes.html">design notes</a>.<p>
313 Fetchmail is a mature project, no longer in constant active
314 development. It is no longer my top project, and I am going to be
315 quite reluctant to add features that might either jeopardize its
316 stability or involve me in large amounts of coding.<p>
318 All that said, if you have a feature idea that really is about a transport
319 problem that can't be handled anywhere but fetchmail, lay it on me. I'm
320 very accommodating about good ideas.<p>
323 <h2><a name="G5">G5. Is there a mailing list for exchanging tips?</a></h2>
325 There is a fetchmail-friends list for people who want to discuss fixes
326 and improvements in fetchmail and help co-develop it. It's at <a
327 href="mailto:fetchmail-friends@thyrsus.com">fetchmail-friends@thyrsus.com</a>.
328 There is also an announcements-only list, <em>fetchmail-announce@thyrsus.com</em>.<P>
330 Both lists are SmartList reflectors; sign up in the usual way with a
331 message containing the word "subscribe" in the subject line sent to
332 <a href="mailto:fetchmail-friends-request@thyrsus.com?subject=subscribe">
333 fetchmail-friends-request@thyrsus.com</a> or
334 <a href="mailto:fetchmail-announce-request@thyrsus.com?subject=subscribe">
335 fetchmail-announce-request@thyrsus.com</a>. (Similarly, "unsubscribe"
336 in the Subject line unsubscribes you, and "help" returns general list help) <p>
339 <h2><a name="G6">G6. So, what's this I hear about a fetchmail paper?</a></h2>
341 The fetchmail development was also a sociological experiment, an
342 extended test to see if my theory about the critical features of the
343 Linux development model is correct.<p>
345 The experiment was a success. I wrote a paper about it titled <a
346 href="http://www.tuxedo.org/~esr/writings/cathedral.html">The
347 Cathedral and the Bazaar</a> which was first presented at Linux
348 Kongress '97 in Bavaria and very well received there. It was also
349 given at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first
350 Perl Conference, at UniForum '98, and was the basis of an invited
351 presentation at Usenix '98. The folks at Netscape tell me it helped
353 href="http://www.netscape.com/newsref/pr/newsrelease558.html"> give
354 away the source for Netscape Communicator</a>.<p>
356 If you're reading a non-HTML dump of this FAQ, you can find the paper
357 on the Web with a search for that title.<p>
360 <h2><a name="G7">G7. What is the best server to use with fetchmail?</a></h2>
362 The short answer: IMAP4rev1 running over Unix.<P>
364 Here's a longer answer: <P>
366 Fetchmail will work with any POP, IMAP, or ESMTP/ETRN server that
367 conforms to the relevant RFCs (and even some outright broken ones like
368 <a href="#S2">Microsoft Exchange</a> and <a href="#S12">Novell
369 GroupWise</a>). This doesn't mean it works equally well with all,
370 however. POP2 servers, and POP3 servers without LAST, limit
371 fetchmail's capabilities in various ways described on the manual
374 Most modern Unixes (and effectively all Linux/*BSD systems) come with
375 POP3 support preconfigured (but beware of the horribly broken POP3
376 server mentioned in <a href="#D2">D2</a>). An increasing minority
377 also feature IMAP (you can detect IMAP support by running fetchmail in
378 AUTO mode, or by using the `Probe for supported protocols' function in
379 the fetchmailconf utility).<P>
381 If you have the option, we recommend using or installing an IMAP4rev1
382 server; it has the best facilities for tracking message `seen' states.
383 It also recovers from interrupted connections more gracefully than
384 POP3, and enables some significant performance optimizations.<P>
386 Don't be fooled by NT/Exchange propaganda. M$ Exchange is just plain
387 broken (see item <a href="#S2">S2</a>) and NT cannot handle the
388 sustained load of a high-volume remote mail server. Even Microsoft
389 itself knows better than to try this; their own Hotmail service runs
390 over Solaris! For extended discussion, see John Kirch's excellent <a
391 href="http://unix-vs-nt.org/kirch/">white paper</a> on Unix
392 vs. NT performance.<P>
394 You can find sources for IMAP software at <a
395 href="http://www.imap.org">The IMAP Connection</a>; we like the
396 open-source <a href="ftp://ftp.cac.washington.edu/imap/">UW IMAP</a>
397 server, which is the reference implementation of IMAP. UW IMAP's
398 support for GSSAPI gives you a good way to authenticate without
399 sending a password en clair.<P>
401 Source for a high-quality supported implementation of POP is available
402 from the <a href="ftp://ftp.qualcomm.com/eudora/servers/unix/popper/">Eudora
403 FTP site</a>. Don't use 2.5, which has a rather restrictive license.
404 The 2.5.2 version appears to restore the open-source license of
405 previous versions.<P>
408 <h2><a name="G8">G8. What is the best mail program to use with fetchmail?</a></h2>
410 Fetchmail will work with all popular <a href="#T1">mail transport programs</a>.
411 It also doesn't care which user agent you use, and user agents are as a
412 rule almost equally indifferent to how mail is delivered into your system
413 mailbox. So any of the popular Unix mail agents --
414 <a href="http://www.myxa.com/old/elm.html">elm</a>,
415 <a href="http://www.washington.edu/pine/">pine</a>
416 <a href="http://www.cs.indiana.edu/docproject/mail/mh.html">mh</a>,
417 or <a href="http://www.mutt.org">mutt</a>
418 -- will work fine with fetchmail.<p>
420 All this having been said, I can't resist putting in a discreet plug
421 for <a href="http://www.mutt.org">mutt</a>. My own personal mail
422 setup is sendmail plus fetchmail plus mutt. Mutt's interface is only
423 a little different from that of its now-moribund ancestor elm, but its
424 excellent handling of MIME and PGP put it in a class by itself. You
425 won't need its built-in POP3 support, though; most of the mutt
426 developers will cheerfully admit that fetchmail's is better :-).<p>
429 <h2><a name="G9">G9. How can I avoid sending my password en clair?</a></h2>
431 Depending on what your mail server you are talking to, this ranges
432 from trivial to impossible. It may even be next to useless.<P>
434 Most people use fetchmail over phone wires, which are hard to tap.
435 Anybody with the skill and resources to do this could get into your
436 server mailbox with much less effort by subverting the server host.
437 So if your provider setup is modem wires going straight into a service
438 box, you probably don't need to worry.<P>
440 In general there is little point in trying to secure your fetchmail
441 transaction unless you trust the security of the server host you are
442 retrieving mail from. Your vulnerability is more likely to be an
443 insecure local network on the server end (e.g. to somebody with a TCP/IP
444 packet sniffer intercepting Ethernet traffic between the modem
445 concentrator you dial in to and the mailserver host).<P>
447 Having realized this, you need to ask whether password encryption
448 alone will really address your security exposure. If you think you
449 might be snooped between server and client, it's better to use
450 end-to-end encryption on your whole mail stream so none of it can be
451 read. One of the advantages of fetchmail over conventional SMTP-push
452 delivery is that you may be able to arrange this by using ssh(1); see
453 <a href="#K3">K3</a>.<P>
455 Note that ssh is not a complete privacy solution either, as your mail
456 could have been snooped in transit to your POP server from wherever it
457 originated. For best security, agree with your correspondents to use
458 a tool such as <a href="http://www.gnupg.org/">GPG</a> (Gnu Privacy
459 Guard) or PGP (Pretty Good Privacy).<P>
461 If ssh/sshd isn't available, or you find it too complicated for you to
462 set up, password encryption will at least keep a malicious cracker
463 from deleting your mail, and require him to either tap your connection
464 continuously or crack root on the server in order to read it.<P>
466 You can deduce what encryptions your mail server has available
467 by looking at the server greeting line (and, for IMAP, the
468 response to a CAPABILITY query). Do a <code>fetchmail -v</code>
469 to see these, or telnet direct to the server port (110 for POP3, 143 for
472 The facility you are most likely to have available is APOP. This is a
473 POP3 feature supported by many servers (fetchmailconf's autoprobe
474 facility will detect it and tell you if you have it). If you see
475 something in the greeting line that looks like an
476 angle-bracket-enclosed Internet address with a numeric left-hand part,
477 that's an APOP challenge (it will vary each time you log in). You can
478 register a secret on the host (using <code>popauth(8)</code> or some
479 program like it). Specify the secret as your password in your
480 .fetchmailrc; it will be used to encrypt the current challenge, and
481 the encrypted form will be sent back the the server for
484 Alternatively, you may have Kerberos available. This may require you
485 to set up some magic files in your home directory on your client
486 machine, but means you can omit specifying any password at all.<P>
488 Fetchmail supports two different Kerberos schemes. One is a
489 POP3 variant called KPOP; consult the documentation of your mail
490 server to see if you have it (one clue is the string "krb-IV" in the
491 greeting line on port 110). The other is an IMAP facility described
492 by RFC1731. You can tell if this one is present by looking for
493 AUTH=KERBEROS_V4 in the CAPABILITY response.<P>
495 If you are fetching mail from a CompuServe POP3 account, you can use
496 their RPA authentication (which works much like APOP). See <a
497 href="#S3">S3</a> for details. If you are fetching mail from
498 Microsoft Exchange, you will be able to use NTLM.<P>
500 Your POP3 server may have the RFC1938 OTP capability to use one-time
501 passwords (if it doesn't, you can get OTP patches for the 2.2 version
502 of the Qualcomm popper from <a href="#cmetz">Craig Metz</a>). To check
503 this, look for the string "otp-" in the greeting line. If you see it,
504 and your fetchmail was built with OPIE support compiled in (see the
505 distribution INSTALL file), fetchmail will detect it also. When using
506 OTP, you will specify a password but it will not be sent en clair.<P>
508 Sadly, there is at present (September 1999) no OTP or APOP-like
509 facility generally available on IMAP servers. However, there do exist
510 patches which will OTP-enable the University of Washington IMAP
511 daemon, version 4.2-FINAL. We have a report that the GSSAPI support
512 in fetchmail works with the GSSAPI support in the most recent version
513 of UW IMAP. Or you can use <a href="#K5">SSL</a> for complete
514 end-to-end encryption if you have an SSL-enabled mailserver.<P>
516 You can get both POP3 and IMAP OTP patches from <a name="cmetz">Craig
518 href="http://www.inner.net/pub/">http://www.inner.net/pub/</a>.<P>
519 These patches use a SASL authentication method named "X-OTP" because
520 there is not currently a standard way to do this; fetchmail also uses
521 this method, so the two will interoperate happily. They better,
522 because this is how Craig gets his mail ;-)<P>
525 <h2><a name="G10">G10. Is any special configuration needed to use a dynamic IP address?</a></h2>
527 Yes. In order to avoid giving indigestion to certain picky MTAs
528 (notably <a href="#T3">exim</a>), fetchmail always makes the RCPT TO
529 address it feeds the MTA a fully qualified one with a hostname part.
530 Normally it does this by appending @ and "localhost", but when you are
531 using Kerberos or ETRN mode it will append @ and your machine's
532 fully-qualified domain name (FQDN).<P>
534 Appending the FQDN can create problems when fetchmail is running in daemon
535 mode and outlasts the dynamic IP address assignment your client
536 machine had when it started up.<P>
538 Since the new IP address (looked up at RCPT TO interpretation time)
539 doesn't match the original, the most benign possible result is that
540 your MTA thinks it's seeing a relaying attempt and refuses. More
541 frequently, fetchmail will try to connect to a nonexistent host
542 address and time out. Worst case, you could up forwarding your mail
543 to the wrong machine!<P>
545 Use the <code>smtpaddress</code> option to force the appended hostname
546 to one with a (fixed) IP address of 127.0.0.1 in your
547 <code>/etc/hosts</code>. (The name `localhost' will usually work; or
548 you can use the IP address itself).<P>
550 Only one fetchmail option interacts directly with your IP address,
551 `<code>interface</code>'. This option can be used to set the gateway
552 device and restrict the IP address range fetchmail will use. Such a
553 restriction is sometimes useful for security reasons, especially on
554 multihomed sites. See <a href="#C3">C3</a>.<P>
556 I recommend against trying to set up the <code>interface</code> option
557 when initially developing your poll configuration -- it's never
558 necessary to do this just to get a link working. Get the link working
559 first, observe the actual address range you see on connections, and
560 add an <code>interface</code> option (if you need one) later.<P>
562 You can't use ETRN if you have a dynamic IP address (your ISP changes
563 your IP address occasionally, possibly with every connect). You need
564 to have your own registered domain and a definite IP address
565 registered for that domain. The server needs to be configured to
566 accept mail for your domain but then queue it to forward to your
567 machine. ETRN just tells to server to flush its queue for your
568 domain. Fetchmail doesn't actually get the mail in that case.<p>
570 If you're using a dynamic-IP configuration, one other (non-fetchmail)
571 problem you may run into with outgoing mail is that some sites will
572 bounce your email because the hostname your giving them isn't real
573 (and doesn't match what they get doing a reverse DNS on your
574 dynamically-assigned IP address). If this happens, you need to hack
575 your sendmail so it masquerades as your host. Setting<P>
581 in your <code>sendmail.cf</code> will work, or you can set<P>
584 MASQUERADE_AS(smarthost.here)
587 in the m4 configuration and do a reconfigure. (In both cases, replace
588 <code>smarthost.here</code> with the actual name of your mailhost.)
589 See the <a href="http://www.lege.com/sendmail-FAQ.txt">sendmail
590 FAQ</a> for more details.<P>
593 <h2><a name="G11">G11. Is any special configuration needed to use firewalls?</a></h2>
595 No. You can use fetchmail with SOCKS, the standard tool for
596 indirecting TCP/IP through a firewall. You can find out about SOCKS,
597 and download the SOCKS software including server and client code, at
598 the <a href="http://www.socks.nec.com/">SOCKS distribution
601 The specific recipe for using fetchmail with a firewall is at <a
605 <h2><a name="G12">G12. Is any special configuration needed to <em>send</em> mail?</a></h2>
607 A user asks: but how do we send mail out to the POP3 server? Do I need
608 to implement another tool or will fetchmail do this too?<p>
610 Fetchmail only handles the receiving side. The sendmail or other
611 preinstalled MTA on your client machine will handle sending mail
612 automatically; it will ship mail that is submitted while the
613 connection is active, and put mail that is submitted while
614 the connection is inactive into the outgoing queue.<P>
616 Normally, sendmail is also run periodically (every 15 minutes on most
617 Linux systems) in a mode that tries to ship all the mail in the
618 outgoing queue. If you have set up something like pppd to
619 automatically dial out when your kernel is called to open a TCP/IP
620 connection, this will ensure that the mail gets out.<P>
623 <h2><a name="G13">G13. Is fetchmail Y2K-compliant?</a></h2>
625 Fetchmail is fully Y2K-compliant.<P>
627 Fetchmail could theoretically have problems when the 32-bit time_t
628 counters roll over in 2038, but I doubt it. Timestamps aren't used
629 for anything but log entry generation. Anyway, if you aren't running
630 on a 64-bit machine by then, you'll deserve to lose.<P>
633 <h2><a name="G14">G14. Is there a way in fetchmail to support disconnected IMAP mode?</a></H2>
635 No. Fetchmail is a mail transport agent, best understood as a protocol
636 gateway between POP3/IMAP servers and SMTP. Disconnected operation
637 requires an elaborate interactive client. It's a very different problem.<p>
640 <h2><a name="G15">G15. How will fetchmail perform under heavy loads?</a></h2>
642 Fetchmail streams message bodies line-by-line; the most core it
643 ever requires per message is enough memory to hold the RFC822 header, and
644 that storage is freed when body processing begins. It is, accordingly,
645 quite economical in its use of memory.<p>
647 After startup time, a fetchmail running in daemon mode stats its
648 configuration file once per poll cycle to see whether it has changed
649 and should be rescanned. Other than that, a fetchmail in normal
650 operation doesn't touch the disk at all; that job is left up to the
651 MTA or MDA the fetchmail talks to.<p>
653 Fetchmail's performance is usually bottlenecked by latency on the POP
654 server or (less often) on the TCP/IP link to the server. This is not
655 a problem readily solved by tuning fetchmail, or even by buying more
656 TCP/IP capacity (which tends to improve bandwidth but not necessarily
660 <h2><a name="B1">B1. Lex bombs out while building the fetchmail lexer.</a></h2>
662 In the immortal words of Alan Cox the last time this came up: ``Take
663 the Solaris lex and stick it up the backside of a passing Sun
664 salesman, then install <a
665 href="ftp://ftp.gnu.org/pub/non-gnu/flex/">flex</a> and use that. All
666 will be happier.''<P>
668 I couldn't have put it better myself, and ain't going to try now.<P>
670 (The same problem has been reported under HP-UX v10.20 and IRIX)<P>
673 <h2><a name="B2">B2. I get link failures when I try to build fetchmail.</a></h2>
675 If you get errors resembling these<P>
678 mxget.o(.text+0x35): undefined referenceto `__res_search'
679 mxget.o(.text+0x99): undefined reference to`__dn_skipname'
680 mxget.o(.text+0x11c): undefined reference to`__dn_expand'
681 mxget.o(.text+0x187): undefined reference to`__dn_expand'
682 make: *** [fetchmail] Error 1
685 then you must add "-lresolv" to the LOADLIBS line in your Makefile
686 once you have installed the `bind' package.<P>
689 <h2><a name="F1">F1. Why does my old .fetchmailrc file no longer work?</a></h2>
691 <h3>If your file predates 5.1.0</h3>
693 In 5.1.0, the <tt>auth</tt> keyword and option were changed to
696 <h3>If your file predates 4.5.5</h3>
698 If the <code>dns</code> option is on (the default), you may need to
699 make sure that any hostname you specify (for mail hosts or for an SMTP
700 target) is a canonical fully-qualified hostname). In order to avoid
701 DNS overhead and complications, fetchmail no longer tries to derive
702 the fetchmail client machine's canonical DNS name at startup.<P>
704 <h3>If your file predates 4.0.6:</h3>
706 Just after the `<CODE>via</CODE>' option was introduced, I realized
707 that the interactions between the `<CODE>via</CODE>',
708 `<CODE>aka</CODE>', and `<CODE>localdomains</CODE>' options were out
709 of control. Their behavior had become complex and confusing, so much so
710 that I was no longer sure I understood it myself. Users were being
711 unpleasantly surprised.<P>
713 Rather than add more options or crock the code, I re-thought it. The
714 redesign simplified the code and made the options more orthogonal, but
715 may have broken some complex multidrop configurations.
717 Any multidrop configurations that depended on the name just after the
718 `<CODE>poll</CODE>' or `<CODE>skip</CODE>' keyword being still
719 interpreted as a DNS name for address-matching purposes, even in the
720 presence of a `<CODE>via</CODE>' option, will break.<P>
722 It is theoretically possible that other unusual configurations (such
723 as those using a non-FQDN poll name to generate Kerberos IV tickets) might
724 also break; the old behavior was sufficiently murky that we can't be
725 sure. If you think this has happened to you, contact the maintainer.<P>
727 <h3>If your file predates 3.9.5:</h3>
729 The `<code>remote</code>' keyword has been changed to `<code>folder</code>'.
730 If you try to use the old keyword, the parser will utter a warning.<P>
732 <h3>If your file predates 3.9:</h3>
734 It could be because you're using a .fetchmailrc that's written in the
735 old popclient syntax without an explicit `<CODE>username</CODE>'
736 keyword leading the first user entry attached to a server entry.
738 This error can be triggered by having a user option such as `<CODE>keep</CODE>'
739 or `<CODE>fetchall</CODE>' before the first explicit username. For
740 example, if you write<p>
743 poll openmail protocol pop3
744 keep user "Hal DeVore" there is hdevore here
747 the `<CODE>keep</CODE>' option will generate an entire user entry with
748 the default username (the name of fetchmail's invoking user).<p>
750 The popclient compatibility syntax was removed in 4.0. It complicated
751 the configuration file grammar and confused users.<p>
753 <h3>If your file predates 2.8:</h3>
755 The `<CODE>interface</CODE>', `<CODE>monitor</CODE>' and
756 `<CODE>batchlimit</CODE>' options changed after 2.8.<p>
758 They used to be global options with `<CODE>set</CODE>' syntax like the
759 batchlimit and logfile options. Now they're per-server options, like
760 `<CODE>protocol</CODE>'.<p>
762 If you had something like<p>
765 set interface = "sl0/10.0.2.15"
768 in your .fetchmailrc file, simply delete that line and insert
769 `interface sl0/10.0.2.15' in the server options part of your `defaults'
772 Do similarly for any `<CODE>monitor</CODE>' or `<CODE>batchlimit</CODE>' options.<p>
775 <h2><a name="F2">F2. The .fetchmailrc parser won't accept my all-numeric user name.</a></h2>
777 Either upgrade to a post-5.0.5 fetchmail or put string quotes around it. :-)<p>
779 The configuration file parser in older fetchmail versions treated any
780 all-numeric token as a number, which confused it when it was
781 expecting a name. String quoting forces the token's class.<p>
783 The lexical analyzer in 5.0.6 and beyond is smarter and assumes
784 any token following "username" or "password" is a string.
787 <h2><a name="F3">F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.</a></h2>
789 See <a href="#F2">F2</a> You're caught in an unfortunate crack between
790 the newer-style syntax for negated options (`no keep', `no rewrite'
791 etc.) and the older style run-on syntax (`nokeep', `norewrite'
794 Upgrade to a 5.0.6 or later fetchmail, or put string quotes around your
798 <h2><a name="F4">F4. I'm getting a `parse error' message I don't understand.</a></h2>
800 The most common cause of mysterious parse errors is putting a server
801 option after a user option. Check the manual page; you'll probably
802 find that by moving one or more options closer to the `poll' keyword
803 you can eliminate the problem.<p>
805 Yes, I know these ordering restrictions are hard to understand.
806 Unfortunately, they're necessary in order to allow the `defaults'
810 <h2><a name="F5">F5. The %h and %p escapes aren't being interporated correctly.</a></h2>
812 Note that %h and %p are only recognized as placeholders if they are a
813 single word each; you cannot use %h:%p or other interpolations that
814 aren't space-delimited. If you happen to need such a thing, write a
815 wrapper. For example, in .fetchmailrc you can add this line:<p>
818 plugin 'mywrap.sh %h %p'
821 With mywrap.sh containing:<p>
825 if test $# -ne 2 ; then
826 echo "usage: `basename $0` <host> <port>"
829 exec openssl 2>/dev/null s_client -connect $1:$2 -quiet
830 exit 2 # never reached unless openssl fails
834 <h2><a name="C1">C1. Why do I need a .fetchmailrc when running as root on my own machine?</a></h2>
836 Ian T. Zimmerman <itz@rahul.net> asked:<p>
838 On the machine where I'm the only real user, I run fetchmail as root
839 from a cron job, like this:<p>
842 fetchmail -u "itz" -p POP3 -s bolero.rahul.net
845 This used to work as is (with no .fetchmailrc file in root's home
846 directory) with the last version I had (1.7 or 1.8, I don't
847 remember). But with 2.0, it RECPs all mail to the local root user,
848 unless I create a .fetchmailrc in root's home directory containing:<p>
851 skip bolero.rahul.net proto POP3
855 It won't work if the second line is just "<CODE>user itz</CODE>". This is silly.<p>
857 It seems fetchmail decides to RECP the `default local user' (i.e. the
858 uid running fetchmail) unless there are local aliases, and the
859 `default' aliases (itz->itz) don't count. They should.<p>
863 No they shouldn't. I thought about this for a while, and I don't much
864 like the conclusion I reached, but it's unavoidable. The problem is
865 that fetchmail has no way to know, in general, that a local user `itz'
868 "Ah!" you say, "Why doesn't it check the password file to see if the remote
869 name matches a local one?" Well, there are two reasons.<p>
871 One: it's not always possible. Suppose you have an SMTP host declared
872 that's not the machine fetchmail is running on? You lose.<p>
874 Two: How do you know server itz and SMTP-host itz are the same person?
875 They might not be, and fetchmail shouldn't assume they are unless
876 local-itz can explicitly produce credentials to prove it (that is, the
877 server-itz password in local-itz's .fetchmailrc file.).<p>
879 Once you start running down possible failure modes and thinking about
880 ways to tinker with the mapping rules, you'll quickly find that all the
881 alternatives to the present default are worse or unacceptably
882 more complicated or both.<p>
885 <h2><a name="C2">C2. How can I arrange for a fetchmail daemon to get killed when I log out?</a></h2>
887 The easiest way to dispatch fetchmail on logout (which will work
888 reliably only if you have just one login going at any time) is to
889 arrange for the command `fetchmail -q' to be called on logout. Under
890 bash, you can arrange this by putting `fetchmail -q' in the file
891 `~/.bash_logout'. Most csh variants execute `~/.logout' on logout.
892 For other shells, consult your shell manual page.<p>
894 Automatic startup/shutdown of fetchmail is a little harder to arrange
895 if you may have multiple login sessions going. In the contrib
896 subdirectory of the fetchmail distribution there is some shell code
897 you can add to your .bash_login and .bash_logout profiles that will
898 accomplish this. Thank James Laferriere <babydr@nwrain.net> for
901 Some people start up and shut down fetchmail using the ppp-up and
902 ppp-down scripts of pppd.<p>
905 <h2><a name="C3">C3. How do I know what interface and address to use with --interface?</a></h2>
907 This depends a lot on your local networking configuration (and right
908 now you can't use it at all except under Linux and the newer BSDs). However,
909 here are some important rules of thumb that can help. If they don't
910 work, ask your local sysop or your Internet provider.<p>
912 First, you may not need to use --interface at all. If your machine
913 only ever does SLIP or PPP to one provider, it's almost certainly by a
914 point to point modem connection to your provider's local subnet that's
915 pretty secure against snooping (unless someone can tap your phone or
916 the provider's local subnet!). Under these circumstances, specifying
917 an interface address is fairly pointless.<p>
919 What the option is really for is sites that use more than one
920 provider. Under these circumstances, typically one of your provider
921 IP addresses is your mailserver (reachable fairly securely via the
922 modem and provider's subnet) but the others might ship your packets
923 (including your password) over unknown portions of the general
924 Internet that could be vulnerable to snooping. What you'll use
925 --interface for is to make sure your password only goes over the
928 To determine the device:<p>
931 <li> If you're using a SLIP link, the correct device is probably sl0.
932 <li> If you're using a PPP link, the correct device is probably ppp0.
933 <li> If you're using a direct connection over a local network such as
934 an ethernet, use the command `netstat -r' to look at your routing table.
935 Try to match your mailserver name to a destination entry; if you don't
936 see it in the first column, use the `default' entry. The device name
937 will be in the rightmost column.
940 To determine the address and netmask:<p>
943 <li> If you're talking to slirp, the correct address is probably 10.0.2.15,
944 with no netmask specified. (It's possible to configure slirp to present
945 other addresses, but that's the default.)
947 <li> If you have a static IP address, run `ifconfig <device>', where <device>
948 is whichever one you've determined. Use the IP address given after
949 "inet addr:". That is the IP address for your end of the link, and is
950 what you need. You won't need to specify a netmask.
952 <li> If you have a dynamic IP address, your connection IP will vary randomly
953 over some given range (that is, some number of the least significant bits
954 change from connection to connection). You need to declare an address
955 with the variable bits zero and a complementary netmask that sets
959 To illustrate the rule for dynamic IP addresses, let's suppose you're
960 hooked up via SLIP and your IP provider tells you that the dynamic
961 address pool is 255 addresses ranging from 205.164.136.1 to
962 205.164.136.255. Then<p>
965 interface "sl0/205.164.136.0/255.255.255.0"
968 would work. To range over any value of the last two octets
969 (65536 addresses) you would use<p>
972 interface "sl0/205.164.0.0/255.255.0.0"
976 <h2><a name="C4">C4. How can I set up support for sendmail's anti-spam features?</a></h2>
978 This answer covers versions of sendmail from 8.8.7 (the version
979 installed in Red Hat 5.1) upwards. If you have an older version,
980 upgrade to sendmail 8.9.<P>
982 Stock sendmails can now do anti-spam exclusions based on a database of
983 filter rules. The human-readable form of the database is at
984 <tt>/etc/mail/deny</tt>. The database itself is at
985 <tt>/etc/mail/deny.db</tt>.<P>
987 The table itself uses email addresses, domain names, and network
988 numbers as keys. For example,</P>
990 spammer@aol.com REJECT
991 cyberspammer.com REJECT
994 <P>would refuse mail from spammer@aol.com, any user from
995 cyberspammer.com (or any host within the cyberspammer.com domain), and
996 any host on the 192.168.212.* network. (This feature can be used to
997 do other things as well; see the <a
998 href="http://www.sendmail.org/m4/anti-spam.html">sendmail
999 documentation</a> for details)</P>
1001 To actually set up the database, run
1004 makemap hash deny <deny
1008 To test, send a message to your mailing address from that host and
1009 then pop off the message with fetchmail, using the -v argument. You
1010 can monitor the SMTP transaction, and when the FROM address is parsed,
1011 if sendmail sees that it is an address in spamlist, fetchmail will
1012 flush and delete it.<p>
1014 Under no circumstances put your <strong>mailhost</strong> or <strong>any host
1015 you accept mail from</strong> using fetchmail into your reject file. You
1016 <strong>will</strong> lose mail if you do this!!!<p>
1019 <h2><a name="C5">C5. How can I poll some of my mailboxes more/less
1020 often than others?</a></h2>
1022 Use the <cite>interval</cite> keyword on the ones that should be
1023 checked less often. For example, if you do a poll every 5 minutes,
1024 and want to poll some mailboxes every 5 minutes and some every 30
1025 minutes, use something like this:<p>
1028 poll mainsite.example.com proto pop3 user ....
1029 poll secondary.example.com proto pop3 interval 6 user ...
1032 Then secondary.example.com will be polled every 6th time that
1033 mainsite.example.com is polled, which with a polling interval of every
1034 5 minutes means that secondary.example.com will be polled every 30
1038 <h2><a name="C6">Fetchmail works OK started up manually, but not from an init script.</a></h2>
1040 Often, startup scripts have a different environment than an interactive
1041 login shell. For instance, $HOME might point to "/root" when you are
1042 logged in as root, but it might be either unset, or set to "/" when the
1043 startup scripts are running. That means fetchmail at startup can't find
1044 the .fetchmailrc.<p>
1046 Pick a location (such as /etc/fetchmailrc) and use fetchmail's -f
1047 option to point fetchmail at it. That should solve the problem.<p>
1050 <h2><a name="C7">C7. How can I forward mail to another host?</a></h2>
1052 To forward mail to a host other than the one you are running fetchmail
1053 on, use the <code>smtphost</code> or <code>smtpname</code> option.
1054 See the manual page for details.<p>
1057 <h2><a name="T1">T1. How can I use fetchmail with sendmail?</a></h2>
1059 For most sendmails, no special configuration is required. Eric Allman
1060 tells me that if <code>FEATURE(always_add_domain)</code> is included
1061 in sendmail's configuration, you can leave the <code>rewrite</code>
1064 If your sendmail complains ``sendmail does not relay'', make sure
1065 your sendmail.cf file says <code>Cwlocalhost</code>
1066 so that sendmail recognizes `localhost' as a name of its host.<p>
1068 If you're mailing from another machine on your local network, also
1069 ensure that its IP address is listed in ip_allow or name in name_allow
1070 (usually in /etc/mail/)<p>
1072 If you find that your sendmail doesn't like the address
1073 `FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail
1074 that fetchmail generates), you may have to set
1075 <code>FEATURE(accept_unqualified_senders)</code>.<P>
1077 Günther Leber reports that Digital Unix sendmails won't work with
1078 fetchmail. The symptom is an error message "<code>553 Local configuration
1079 error, hostname not recognized as local</code>". The problem is that
1080 fetchmail normally feeds sendmail with the client machine's host
1081 address in the MAIL FROM line. These sendmails think this means
1082 they're seeing the result of a mail loop and suppress the mail. You
1083 may be able to work around this by running in <code>--invisible</code> mode.<P>
1085 If you want to support multidrop mode, and you can get access to your
1086 mailserver's sendmail.cf file, it's a good idea to add this rule:<P>
1089 H?l?Delivered-To: $h
1092 This will cause the mailserver's sendmail to reliably write the
1093 appropriate envelope address into each message before fetchmail sees
1094 it, and tell fetchmail which header it is. With this change,
1095 multidrop mode should work reliably even when the Received header
1096 omits the envelope address (which will typically be the case when
1097 the message has multiple recipients). However it will still not
1098 distinguish the recipients, your only advantage is that no bounce
1099 will be sent if a message is BCC addressed to multiple users at
1100 your site. To fix even that problem, you might want to try the
1101 following hack, which is however untested and quite experimental:<P>
1104 H?J?Delivered-To: $u
1106 Mmdrop, P=/usr/bin/procmail, F=lsDFMqSPfhnu9J,
1107 S=EnvFromSMTP/HdrFromSMTP, R=EnvToSMTP/HdrToSMTP,
1108 T=DNS/RFC822/X-Unix,
1109 A=procmail -Y -a $u -d $h
1112 For both hacks, you have to declare `<CODE>envelope "Delivered-To:"</CODE>' on
1113 the fetchmail side, to put the virtual domain (e.g. `domain.com')
1114 with RELAY permission into your access file and to add a line
1115 reading `<CODE>domain.com local:local-pop-user</CODE>' for the first and
1116 `<CODE>domain.com mdrop:local-pop-user</CODE>' for the second hack to your
1119 You will notice that if the mail already has a Delivered-To header,
1120 sendmail will not add another. Further, editing sendmail.cf
1121 directly is not very comfortable. Solutions for both problems
1122 can be found in Peter `Rattacresh' Backes' `hybrid' patch against
1123 sendmail. Have a look at it, you can find it in the contrib
1126 Feel free to try Martijn Lievaart's detailed recipe in the contrib
1127 subdirectory of the fetchmail source distribution, it attempts
1128 to realize multidrop mailboxes with an external script.<P>
1131 <h2><a name="T2">T2. How can I use fetchmail with qmail?</a></h2>
1133 Turn on the <CODE>forcecr</CODE> option; qmail's listener mode doesn't like
1134 header or message lines terminated with bare linefeeds.<p>
1136 (This information is thanks to Robert de Bath
1137 <robert@mayday.cix.co.uk>.)<p>
1139 If a mailhost is using the qmail package (see <a
1140 href="http://pobox.com/~djb/qmail.html">http://pobox.com/~djb/qmail.html</a>)
1141 then, providing the local hosts are also using qmail, it is possible
1142 to set up one fetchmail link to be reliably collect the mail for an
1145 One of the basic features of qmail is the `Delivered-To:' message
1146 header. Whenever qmail delivers a message to a local mailbox it puts
1147 the username and hostname of the envelope recipient on this line. The
1148 major reason for this is to prevent mail loops. <p>
1150 To set up qmail to batch mail for a disconnected site the ISP-mailhost
1151 will have normally put that site in its `virtualhosts' control file so
1152 it will add a prefix to all mail addresses for this site. This results
1153 in mail sent to 'username@userhost.userdom.dom.com' having a
1154 'Delivered-To:' line of the form:<p>
1157 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
1160 A single host maildrop will be slightly simpler:
1163 Delivered-To: mbox-userstr-username@userhost.dom.com
1166 The ISP can make the 'mbox-userstr-' prefix anything they choose
1167 but a string matching the user host name is likely.<p>
1169 To use this line you must:<p>
1172 <li>Ensure the option `envelope Delivered-To:' is in the fetchmail
1175 <li>Ensure you have a localdomains containing 'userdom.dom.com' or
1176 `userhost.dom.com' respectively.
1179 So far this reliably delivers messages to the correct machine of the
1180 local network, to deliver to the correct user the 'mbox-userstr-'
1181 prefix must be stripped off of the user name. This can be done by
1182 setting up an alias within the qmail MTA on each local machine.
1183 Simply create a dot-qmail file called '.qmail-mbox-userstr-default'
1184 in the alias directory (normally /var/qmail/alias) with the contents:<p>
1187 | ../bin/qmail-inject -a -f"$SENDER" "${LOCAL#mbox-userstr-}@$HOST"
1190 Note this <em>does</em> require a modern /bin/sh.<p>
1192 Peter Wilson adds: <P>
1194 ``My ISP uses "alias-unzzippedcom-" as the prefix, which means that I
1195 need to name my file ".qmail-unzzippedcom-default". This is due to
1196 qmail's assumption that a message sent to user-xyz is handled by the
1197 file ~user/.qmail-xyz (or ~user/.qmail-default).''<p>
1199 Luca Olivetti adds:<P>
1201 If you aren't using qmail locally, or you don't want to set up the
1202 alias mechanism described above, you can use the option `<code>qvirtual
1203 "mbox-userstr-"</code>' in your fetchmail config file to strip the prefix
1204 from the local user name.<p>
1207 <h2><a name="T3">T3. How can I use fetchmail with exim?</a></h2><p>
1209 If you have <CODE>rewrite</CODE> on: <P>
1211 There is an RFC1123 requirement that MAIL FROM and RCPT TO addresses
1212 you pass to it have to be canonical (e.g. with a fully qualified
1213 hostname part). Therefore fetchmail tries to pass fully qualified
1214 RCPT TO addresses. But exim does not by default accept `localhost' as
1215 a fully qualified domain. This can be fixed.<P>
1217 In exim.conf, add `localhost' to your local_domains declaration if it's not
1218 already present. For example, the author's site at thyrsus.com would
1219 have a line reading:<P>
1222 local_domains = thyrsus.com:localhost
1225 If you have <CODE>rewrite</CODE> off:<P>
1227 MAIL FROM is a potential problem if the MTAs upstream from your fetchmail
1228 don't necessarily pass canonicalized From and Return-Path addresses,
1229 and fetchmail's <CODE>rewrite</CODE> option is off. The specific case
1230 where this has come up involves bounce messages generated by sendmail
1231 on your mailer host, which have the (un-canonicalized) origin address
1234 The right way to fix this is to enable the <CODE>rewrite</CODE> option and
1235 have fetchmail canonicalize From and Return-Path addresses with the
1236 mailserver hostname before exim sees them. This option is enabled by
1237 default, so it won't be off unless you turned it off.<p>
1239 If you must run with <CODE>rewrite</CODE> off, there is a switch in exim's
1240 configuration files that allows it to accept domainless MAIL FROM
1241 addresses; you will have to flip it by putting the line <p>
1244 sender_unqualified_hosts = localhost
1247 in the main section of the exim configuration file. Note that this
1248 will result in such messages having an incorrect domain name attached
1249 to their return address (your SMTP listener's hostname rather than
1250 that of the remote mail server). <p>
1253 <h2><a name="T4">T4. How can I use fetchmail with smail?</a></h2><p>
1255 Smail 3.2 is very nearly plug-compatible with sendmail, and may work
1256 fine out of the box.<P>
1258 We have one report that when processing multiple messages from a
1259 single fetchmail session, smail sometimes delivers them in an
1260 order other than received-date order. This can be annoying because it
1261 scrambles conversational threads. This is not fetchmail's problem,
1262 it is an smail `feature' and has been reported to the maintainers
1265 Very recent smail versions require an <code>-smtp_hello_verify</code>
1266 option in the smail config file. This overrides smail's check to see
1267 that the HELO address is actually that of the client machine, which
1268 is never going to be the case when fetchmail is in the picture.
1269 According to RFC1123 an SMTP listener <em>must</em> allow this
1270 mismatch, so smail's new behavior (introduced sometime between
1271 3.2.0.90 and 3.2.0.95) is a bug.<P>
1274 <h2><a name="T5">T5. How can I use fetchmail with SCO's MMDF?</a></h2><p>
1276 MMDF itself is difficult to configure, but it turns out that
1277 connecting fetchmail to MMDF's SMTP channel isn't that hard.
1279 href="http://www.aplawrence.com/Unixart/uucptofetch.html">
1280 MMDF recipe</a> that describes replacing a UUCP link with
1281 fetchmail feeding MMDF.<P>
1284 <h2><a name="T6">T6. How can I use fetchmail with Lotus Notes?</a></h2><p>
1286 The Lotus Notes SMTP gateway tries to deduce when it should convert \n
1287 to \r\n, but its rules are not the intuitive and correct-for-RFC822
1288 ones. Use `forcecr'.<P>
1291 <h2><a name="S1">S1. How can I use fetchmail with qpopper?</a></h2>
1293 Qualcomm's qpopper is probably the best-of-breed among POP3 servers, and
1294 is very widely deployed. Nevertheless, it has some problems which
1295 fetchmail exposes. We recommend using <a href="#G7">IMAP</a> instead if at
1296 all possible. If you must talk to qpopper, here are some problems to
1299 <h3>Problems with retrieving large messages from qpopper 2.53</h3>
1301 Tony Tang <a href="mailto:tony@atn.com.hk"><tony@atn.com.hk></a>
1302 reports that there is a bad intercation between fetchmail and qpopper
1303 2.5.3 under Red Hat Linux versions 5.0 to 5.2, kernels 2.0.34 to
1304 2.0.35. When fetching very large messages (over 700K) from 2.5.3,
1305 fetchmail will hang with a socket error.<p>
1307 This is probably not a fetchmail bug, but rather a symptom of some
1308 problem in the networking stack that qpopper's transmission pattern is
1309 tickling, as fetchpop (another Linux POP client) also displays the hang
1310 but Netscape running under Win95 does not. The problem can also be
1312 href="http://www.eudora.com/freeware/qpop.html">upgrading to qpopper
1315 <h3>Bad interaction with fetchmail 4.4.2 to 4.4.7</h3>
1317 Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction
1318 with Eudora qpopper versions 2.3 and later. See <a href="#X5">X5</a>
1319 for details. The solution is to upgrade your fetchmail.<p>
1322 <h2><a name="S2">S2. How can I use fetchmail with Microsoft Exchange?</a></h2>
1324 Fetchmail now supports the proprietary NTLM mode used with M$ Exchange
1325 servers. To enable this, configure fetchmail with the --enable-NTLM
1326 option and recompile it. Note: if you specify a user option value
1327 that looks like `user@domain', the part to the left of the @ will
1328 be passed as the username and the part to the right as the NTLM domain.<P>
1330 M$ Exchange violates the POP3 RFCs. Its LIST command does not reveal
1331 the real sizes of mail in the pop mailbox, but the sizes of the
1332 compressed versions in the exchange mail database (thanks to Arjan De
1333 Vet and Guido Van Rooij for alerting us to this problem).<P>
1335 Fetchmail works with M$ Exchange, despite this brain damage. Two
1336 features are compromised. One is that the --limit option will not
1337 work right (it will check against compressed and not actual sizes).
1338 The other is that a too-small SIZE argument may be passed to your
1339 ESMTP listener, assuming you're using one (this should not be a
1340 problem unless the actual size of the message is above the listener's
1341 configured length limit).<P>
1343 Somewhat belatedly, I've learned that there's supposed to be a
1344 registry bit that can fix this breakage:<P>
1347 HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1348 System\Pop3 Compatibility
1351 This is a bitmask that controls the variations from the standard protocol.
1352 The bits defined are:<P>
1356 <DD>Report exact message sizes for the LIST command
1358 <DD>Allow arbitrary linear whitespace between commands and arguments
1360 <DD>Enable the LAST command
1362 <DD>Allow an empty PASS command (needed for users with blank
1363 passwords, but illegal in the protocol)
1365 <DD>Relax the length restrictions for arguments to commands (protocol
1366 requires 40, but some user names may be longer than that).
1368 <DD>Allow spaces in the argument to the USER command.
1371 There's another one that may be useful to know about:<P>
1374 KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1375 System\Pop3 Performance
1380 <DD>Render messages to a temporary stream instead of sending directly
1381 from the database (should always be on)
1383 Flag unrenderable messages (instead of just failing commands)
1384 (should only be on if you are seeing the problems reported
1387 <DD>Return from the QUIT command before all messages have been deleted.
1390 The Microsoft pod-person who revealed this information to me admitted
1391 that he couldn't find it anywhere in their public knowledge base.<P>
1393 Another specific problem we have seen with Exchange servers has as its
1394 symptom a response to LOGIN that says "NO Ambiguous Alias". Grant
1397 This means that Exchange Server is too f*&#ing stupid to figure
1398 out which mailbox belongs to you. Instead of actually keeping
1399 track of which inbox belongs to which user, it uses some
1400 half-witted, guess-o-matic heuristic to try to guess your
1401 mailbox name from your username.<p>
1403 In your case it doesn't work because your username maps to more
1404 than one mailbox. For some people it doesn't work because
1405 their username maps to zero mailboxes. This is yet another
1406 inept, lame, almost criminally negligent design decision from
1407 our friends in Redmond.<p>
1409 You've got several options:
1413 Try giving fetchmail a username of "/NTDomain/NTUsername/MailboxName".
1415 Get your administrator to configure the server so that
1416 usernames and mailbox names are the same.
1418 Get your administrator to add an alias that maps your
1419 username explicitly to your mailbox name.
1422 But, the best option involves a tactical nuclear weapon (an old
1423 ASROC will do), pissing off a lot people who live downwind from
1424 Redmond, and your choice of any Linux, NetBSD, FreeBSD, or
1427 I'll provide the CD.
1430 <h2><a name="S3">S3. How can I use fetchmail with CompuServe RPA?</a></h2>
1432 First, make sure your fetchmail has the RPA support compiled in.
1433 Stock fetchmail binaries (such as you might get from an RPM) don't.
1434 You can check this by looking at the output of <code>fetchmail -V</code>;
1435 if you see the string "+RPA" after the version ID you're good to go,
1436 otherwise you'll have to build your own from sources (see the INSTALL
1437 file in the source distribution for directions).<P>
1439 Give your CompuServe pass-phrase in lower case as your password. Add
1440 `@compuserve.com' to your user ID so that it looks like `user
1441 <UserID>@compuserve.com', where <UserID> can be either
1442 your numerical userID or your E-mail nickname. An RPA-enabled
1443 fetchmail will automatically check for csi.com in the POP server's
1444 greeting line. If that's found, and your user ID ends with
1445 `@compuserve.com', it will query the server to see if it
1446 is RPA-capable, and if so do an RPA transaction rather than a
1447 plain-text password handshake.<P>
1449 <strong>Warning:</strong> the debug (-v -v) output of fetchmail will show
1450 your pass-phrase in Unicode!<P>
1452 These two .fetchmailrc entries show the difference between an RPA and
1453 non-RPA configuration:
1456 # This version will use RPA
1457 poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1458 user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
1459 is LOCAL_USER here options fetchall stripcr
1461 # This version will not use RPA
1462 poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1463 user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
1464 is LOCAL_USER here options fetchall stripcr
1468 <h2><a name="S4">S4. How can I use fetchmail with Demon Internet's SDPS?</a></h2>
1470 <h3>Single-drop mode</h3>
1472 You can get fetchmail to download the email for just one user from
1473 Demon Internet's POP3 server by giving it a username consisting of your
1474 Demon user name followed by your account name, with an at-sign between
1477 For example, to download email for the user <philh@vision25.demon.co.uk>,
1478 you could use the following .fetchmailrc file:<P>
1481 set postmaster "philh"
1482 poll pop3.demon.co.uk with protocol POP3:
1483 user "philh@vision25" is philh
1486 <h3>Multi-drop mode</h3>
1488 Demon Internet's SDPS service is an implementation of POP3. All messages
1489 have a Received: header added when they enter the maildrop, like this:
1492 Received: from punt-1.mail.demon.net by mailstore.com for fred@xyz.demon.co.uk
1493 id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT
1496 To enable multi-drop mode you need to tell fetchmail that 'mailstore.com' is
1497 the name of the host which accepted the mail, and let it know the
1498 hostname part(s) of your E-mail address. The following example assumes
1499 that your hostname is xyz.demon.co.uk, and that you have also bought
1500 "mail forwarding" for the domain my-company.co.uk (in which case your
1501 MTA must also be configured to accept mail sent to user@my-company.co.uk)
1504 poll pop3.demon.co.uk proto pop3 aka mailstore.com no dns:
1505 localdomains xyz.demon.co.uk my-company.co.uk
1506 user xyz is * fetchall
1509 The `fetchall' command ensures that all mail is downloaded. If you
1510 want to leave mail on the server use `uidl' and `keep'; Demon does not
1511 implement the obsolete `top' command, because SDPS combines messages
1512 residing on two separate punt clusters into a single POP3 maildrop.
1513 If you do use UIDL, be aware that the "user@host" form for fetching
1514 mail from a particular Demon host will confuse fetchmail's UIDL code;
1517 Note that Demon may delete mail on the server which is more than 30
1518 days old; see their <a
1519 href="http://www.demon.net/info/helpdesk/demon_products/mail/sdps-tech.shtml">
1520 POP3 page</a> for details.<P>
1522 <h3>The SDPS extension</h3>
1524 There's a different way to do multidrop. It's not necessary on Demon
1525 Internet, since fetchmail can parse Received addresses, but the person
1526 who implemented this didn't know that. It may be useful if Demon
1527 Internet ever changes mail transports.<P>
1529 SDPS includes a non-standard extension for retrieving the envelope of a
1530 message (*ENV), which fetchmail optionally supports if compiled with the
1531 --enable-SDPS option. If you have it, the first line of the fetchmail -V
1532 response will include the string "+SDPS".<P>
1534 Once you have SDPS compiled in, fetchmail in POP3 mode will
1535 automatically detect when it's talking to a Demon Internet host in
1536 multidrop mode, and use the *ENV extension to get an envelope To address.<P>
1538 The autodetection works by looking at the hostname in the POP3
1539 greeting line; if you're accessing Demon Internet through a proxy it
1540 may fail. To force SDPS mode, pick "sdps" as your protocol.<P>
1543 <h2><a name="S5">S5. How can I use fetchmail with usa.net's servers?</a></h2>
1545 Enable `<CODE>fetchall</CODE>'. A user reports that the 2.2 version
1546 of USA.NET's POP server reports that you must use the
1547 `<CODE>fetchall</CODE>' option to make sure that all of the mail is
1548 retrieved, otherwise some may be left on the server. This is almost
1549 certainly a server bug.<P>
1551 The usa.net servers (at least in their 2.2 version, June 1998) don't
1552 handle the TOP command properly, either. Regardless of the argument
1553 you give it, they retrieve only about 10 lines of the message.
1554 Fetchmail normally uses TOP for message retrieval in order to avoid
1555 marking messages seen, but `<CODE>fetchall</CODE>' forces it to use
1558 (Note: Other failure modes have been reported on usa.net's servers.
1559 They seem to be chronically flaky. We recommend finding another
1563 <h2><a name="S6">S6. How can I use fetchmail with HP OpenMail?</a></h2>
1565 No special configuration is required, but OpenMail versions prior to
1566 6.0 have an annoying bug similar to the big one in <a
1567 href="#S2">Microsoft Exchange</a>. The message sizes it gives in the
1568 LIST are rounded to the nearest 1024 bytes. It also has a nasty habit
1569 of discarding headers it doesn't recognize, such as X- and Resent-
1572 As with M$ Exchange, the only real fix for these problems is to get a
1573 POP (or preferably IMAP) server that isn't brain-dead. OpenMail's
1574 project manager claims these bugs have been fixed in 6.0.<P>
1577 <h2><a name="S8">S8. How can I use fetchmail with Hotmail?</a></h2>
1579 You can't, yet. But <a
1580 href="http://www.ozemail.com.au/~peterhawkins/gotmail/">gotmail</a>
1581 might be what you need.<P>
1584 <h2><a name="S9">S9. How can I use fetchmail with MSN?</a></h2>
1586 You can't. MSN uses something that looks like POP3, except the
1587 authentication part is nonstandard. And of course they don't
1588 document it, so nobody but their Windows clients can speak it.<p>
1590 This is a customer lock-in tactic; we recommend boycotting MSN as the
1591 only appropriate response.<p>
1593 As of 5.0.8, we have support for the client side of NTLM
1594 authentication. It's possible this may enable fetchmail to talk to
1595 MSN; if so, somebody should report it so this FAQ can be corrected.<p>
1598 <h2><a name="S10">S10. How can I use fetchmail with SpryNet?</a></h2>
1600 The SpryNet POP3 servers mark a message queried with TOP as seen.
1601 This means that if your connection drops in mid-message, it may end
1602 up invisibly stuck on your mail spool. Use the <code>fetchall</code>
1603 flag to ensure that it's recovered on the next cycle.<p>
1606 <h2><a name="S11">S11. How can I use fetchmail with FTGate?</a></h2>
1608 The FTGate V2 server (and possibly older versions as well) has a weird
1609 bug. It answers OK twice to a TOP request! Use the
1610 <code>fetchall</code> option to force use of RETR and work around this
1614 <h2><a name="S12">S12. How can I use fetchmail with MailMax?</a></h2>
1616 You can't. At least not if you want to be able to see attachments.
1617 MailMax has a bug; it reports the message length with attachments
1618 but doesn't download them on TOP or RETR.<P>
1620 Also, we're told that TOP sometimes fails to retrieve the entire
1621 message even when enough lines have been specified. The MailMax
1622 developers have acknowledged this bug as of 4 May 2000, but there is
1623 no fix yet. If you must use this server, force RETR with the
1624 <tt>fetchall</tt> option.<p>
1627 <h2><a name="S13">S13. How can I use fetchmail with Novell GroupWise?</a></h2>
1629 The Novell GroupWise IMAP server would be better named GroupFoolish;
1630 it is (according to the designer of IMAP) unusably broken. Among
1631 other things, it doesn't include a required content length in its
1632 BODY[TEXT] response.<p>
1634 Fetchmail works around this problem, but we strongly recommend voting
1635 with your dollars for a server that isn't brain-dead. If you stick
1636 with code as shoddy as GroupWise seems to be, you will probably pay
1637 for it with other problems.<p>
1640 <h2><a name="S14">S14. How can I use fetchmail with InterChange?</a></h2>
1642 You can't. At least not if you want to be able to see attachments.
1643 InterChange has a bug similar to the MailMax server; it reports the
1644 message length with attachments but doesn't download them on TOP or
1648 <h2><a name="K1">K1. How can I use fetchmail with SOCKS?</a></h2>
1650 Giuseppe Guerini added a --with-socks option that supports linking
1651 with socks library. If you specify the value of this option as
1652 ``yes'', the configure script will try to find the Rconnect library
1653 and set the makefile up to link it. You can also specify a directory
1654 containing the Rconnect library.<p>
1656 Alan Schmitt has added a similar --with-socks5 option that may work
1657 better if you have a recent version of the SOCKS library.
1660 <h2><a name="S7">S7. How can I use fetchmail with geocities POP3 servers?</a></h2>
1662 Nathan Cutler reports that the the mail.geocities.com POP3 servers
1663 fail to include the first Received line of the message in the send to
1664 fetchmail. This can solve problems if your MUA interprets Received
1665 continuations as body lines and doesn't parse any of the following
1668 Workaround is to use "mda" keyword or "-mda" switch:
1670 mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d <user>"
1672 Replace \t with exactly one tabulation character.
1674 You should also consider using "fetchall" option because Geocities' servers
1675 sometimes think that the first 45 messages have already been read.<P>
1677 Fix: Get an email provider that doesn't suck. The pop-up ads on
1678 Geocities are lame, you should boycott them anyway.<P>
1681 <h2><a name="K2">K2. How can I use fetchmail with IPv6 and IPsec?</a></h2>
1683 To use fetchmail with IPv6, you need a system that supports IPv6, the "Basic
1684 Socket Interface Extensions for IPv6" (RFC 2133).
1685 This currently means that you need to have a BSD/OS or NetBSD system with
1686 the NRL IPv6+IPsec software distribution or a Linux system with a 2.2 or
1687 later kernel and net-tools. It should not be hard to build fetchmail on
1688 other IPv6 implementations if you can port the inet6-apps kit.<P>
1690 To use fetchmail with networking security (read: IPsec), you need a system that
1691 supports IPsec, the API described in the "Network Security API for Sockets"
1692 (draft-metz-net-security-api-01.txt), and the inet6-apps kit. This currently
1693 means that you need to have a BSD/OS or NetBSD system with the NRL IPv6+IPsec
1694 software distribution. A Linux IPsec implementation supporting this API will
1695 probably appear in the coming months.<P>
1697 The NRL IPv6+IPsec software distribution can be obtained from: <a
1698 href="http://web.mit.edu/network/isakmp">http://web.mit.edu/network/isakmp</a>
1701 The inet6-apps kit can be obtained from <a href="http://ftp.ps.pl/pub/linux/IPv6/inet6-apps/">http://ftp.ps.pl/pub/linux/IPv6/inet6-apps/</a>.<P>
1703 More information on using IPv6 with Linux can be obtained from:
1706 <a href="http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html">
1707 http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html</a>
1709 <a href="http://www.ipv6.inner.net/ipv6">http://www.ipv6.inner.net/ipv6</a>
1712 <a href="http://www.inner.net/ipv6">http://www.inner.net/ipv6</a> (via IPv4)
1716 <h2><a name="K3">K3. How can I get fetchmail to work with ssh?</a></h2>
1718 We have five recipes for this.<P>
1720 <h3>Single-User POP3</h3>
1722 First, a lightly edited version of a recipe from Masafumi NAKANE.
1723 This one is easy to set up, but only supports one user at a time.<p>
1725 1. You must have ssh (the ssh client) on the local host and sshd (ssh
1726 server) on the remote mail server. And you have to configure ssh so
1727 you can login to the sshd server host without a password. (Refer to ssh
1728 man page for several authentication methods.)<p>
1730 2. Add something like following to your .fetchmailrc file: <p>
1733 poll mailhost port 1234 via localhost with proto pop3:
1734 preconnect "ssh -l username -f mailhost -L 1234:mailhost:110 sleep 5"
1737 The sleep is needed on slower machines to prevent fetchmail from
1738 trying to open the socket before ssh actually makes it ready. Faster
1739 machines may not need it.<p>
1741 (Note that 1234 can be an arbitrary port number. Privileged ports can
1742 be specified only by root.) The effect of this ssh command is to
1743 forward connections made to localhost port 1234 (in above example) to
1746 This configuration will enable secure mail transfer. All the
1747 conversation between fetchmail and remote pop server will be
1750 If sshd is not running on the remote mail server, you can specify
1751 intermediate host running it. If you do this, however, communication
1752 between the machine running sshd and the POP server will not be encrypted.
1753 And the preconnect line would be like this:<p>
1756 preconnect "ssh -f -L 1234:mailhost:110 sshdhost sleep 20 </dev/null >/dev/null"
1759 You can work this trick with IMAP too, but the port number 110 in the
1760 above would need to become 143. In either case you'll have to specify
1761 a password but the password will not be sent in clear.<p>
1763 There is an explanation of a similar recipe at <a
1764 href="http://sunsite.unc.edu/LDP/HOWTO/mini/Secure-POP+SSH.html">Secure
1765 POP via SSH mini-HOWTO</a>.<P>
1767 <h3>Multi-User POP3</h3>
1769 Second, a recipe from Charlie Brady <cbrady@ind.tansu.com.au>:<p>
1771 Charlie says: "The recipe [from Masafume NAKANE] certainly works, but
1772 the solution I post here is better in a few respects":
1775 <LI>this method will not fail if two or more users attempt to use fetchmail
1777 <LI>you are able to use the full facilities of tcpd to control access
1778 <LI>this method does not depend on the preconnect feature of fetchmail, so
1779 can be used for tunneling of other services as well.
1786 Make sure that the "socket" program is installed on the server
1787 machine. Presently it lives at <a
1788 href="ftp://sunsite.unc.edu/pub/linux/system/network/misc/socket-1.1.tar.gz">
1789 ftp://sunsite.unc.edu/pub/linux/system/network/misc/socket-1.1.tar.gz</a>,
1790 but watch out for a change in version number.<P>
1792 Set up an unprivileged account on your system with a .ssh directory
1793 containing an SSH identity file "identity" with no pass phrase,
1794 "identity.pub" and "known_hosts" containing the host key of your
1795 mailhost. Let's call this account "noddy".
1797 On mailhost, set up no-password access for noddy@yourhost. Add to your
1798 SSH authorized_keys file:
1801 command="socket localhost 110",no-port-forwarding 1024 ......
1804 where "<code>1024 ......</code>" is the content of noddy's identity.pub file.
1806 Create a script /usr/local/bin/ssh.fm and make it executable:
1810 exec ssh -q -C -l your.login.id -e none mailhost socket localhost 110
1813 Add an entry in inetd.conf for whatever port you choose to use - say:
1816 1234 stream tcp nowait noddy /usr/sbin/tcpd /usr/local/bin/ssh.fm
1819 Send a HUP signal to your inetd.
1822 Now just use localhost:1234 to access your POP server.<P>
1824 <h3>Multi-User IMAP</h3>
1826 This one comes comes to us from Joerg Dorchain.
1827 The basic idea is to set up a bidirectional encrypted socket connection:<p>
1830 fetchmail <--> ssh <---> sshd <--> imapd
1831 \---local side--/ \-remote side-/
1834 Use ssh-keygen(1) to set up a special ssh identity with no password
1835 and RSA-only authentication, which executes /usr/sbin/imapd when
1836 authenticated. For security reasons all other commands should be
1837 disabled. (There is some security exposure in using an identity
1838 without a passphrase; it means anyone who can get access to your
1839 account could use it to read your mail).<p>
1841 Running ssh-keygen will generate two files. Have it create the
1842 private key to ~/.ssh/identity-imap. Once you have generated the
1843 corresponding public key, prepend this to the line of key data in it:
1846 command="/usr/sbin/imapd",no-port-forwarding,no-agent-forwarding
1849 This identity data has to be appended to ~/.ssh/authorized_keys on the
1850 remote machine, as usual for RSA authentication. Whenever your ssh
1851 uses this identity, the remote side will run imapd. The imapd will
1852 see that it is not running as root and go into preauthenticated
1855 On the client side, use the <code>plugin</code> keyword to make
1856 fetchmail talk to the stdin of the remote ssh. Here's an examople:
1859 poll mail.dorchain.net
1860 with options proto imap, preauth ssh, plugin fetchmail-imap-wrapper
1863 The wrapper script should look like this:<p>
1867 exec ssh -i $HOME/.ssh/identity-imap $1 /usr/sbin/imapd
1870 <h3>Netcat-based POP or IMAP tunnelling</h3>
1872 Oren Tirosh <oren@mimique.com> sends us a method of using
1873 fetchmail over ssh without port forwarding, using the plugin keyword.<P>
1875 First, set up a poll entry resembling thius one:
1878 poll target.host plugin sshtunnel proto pop3 user foo password *
1881 The important part is the "plugin sshtunnel". Now set up sshtunnel
1885 This is the sshtunnel script:
1887 ssh $1 "nc localhost $2"
1890 Thia method uses netcat to connect to the pop3 port locally on the
1891 target host and create a two-way channel over the ssh connection.<P>
1893 Oren says: "In my experience it is much more reliable than the methods
1894 described in your FAQ. ssh port forwarding often keeps the local port
1895 bound for along timeout and has timing issues requiring tricks like
1896 sleep, etc. I use this method for fetching all the mail for
1899 <h3>Using plugin</h3>
1901 Since 5.4.5, there's been a very simple recipe. Use the following option:
1904 plugin "ssh %h /usr/sbin/rimapd"
1907 You may have to use a different absolute pathname. This option tells
1908 fetchmail that instead of opening a connection on the server's port
1909 143 and doing standard IMAP authentication, fetchmail should ssh to
1910 the server and run rimapd, using the more secure ssh authentication
1911 (as well as getting ssh's encryption).<p>
1914 <h2><a name="K4">K4. What do I have to do to use the IMAP-GSS protocol?</a></h2>
1916 Fetchmail can use RFC1731 GSSAPI authorization to safely identify you
1917 to your IMAP server, as long as you can share Kerberos V credentials
1918 with your mail host and you have a GSSAPI-capable IMAP server.
1919 UW-IMAP (available via FTP at <a
1920 href="ftp://ftp.cac.washington.edu/mail/">ftp.cac.washington.edu</a>)
1921 is the only one I'm aware of and the one I recommend anyway for other
1922 reasons. You'll need version 4.1-FINAL or greater though, and it has
1923 to have GSS support compiled in.<p>
1925 Neither UW-IMAP nor fetchmail compile in support for GSS by default,
1926 since it requires libraries from the Kerberos V distribution
1927 (available via FTP at <a
1928 href="ftp://athena-dist.mit.edu/pub/ATHENA/kerberos">athena-dist.mit.edu</a>).
1929 If you have these, compiling in GSS support is simple: add a
1930 <pre>--with-gssapi=[/path/to/krb5/root]</pre> option to configure. For
1931 instance, I have all of my Kerberos V libraries installed under
1932 /usr/krb5 so I run <pre>configure --with-gssapi=/usr/krb5</pre><p>
1934 Setting up Kerberos V authentication is beyond the scope of this FAQ
1935 (you may find Jim Rome's paper <a
1936 href="http://www.ornl.gov/~jar/HowToKerb.html"> How to Kerberize your
1937 site</a> helpful), but you'll at least need to add a credential for
1938 imap/[mailhost] to the keytab of the mail server (IMAP doesn't just
1939 use the host key). Then you'll need to have your credentials ready on
1940 your machine (cf. kinit).<p>
1942 After that things are very simple. Set your protocol to imap-gss in your
1943 .fetchmailrc, and omit the password, since imap-gss doesn't need one. You
1944 can specify a username if you want, but this is only useful if your mailbox
1945 belongs to a username different from your Kerberos principal. <p>
1947 Now you don't have to worry about your password appearing in cleartext in
1948 your .fetchmailrc, or across the network.<p>
1951 <h2><a name="K5">K5. How can I use fetchmail with SSL?</a></h2>
1953 You'll need to have the <a href="http://www.openssl.org/">OpenSSL</a>
1954 libraries installed. Configure with --with-ssl. If you have the
1955 OpenSSL libraries installed in the default location (/usr/local/ssl)
1956 this will suffice. If you have them installed in a non-default
1957 location, you'll need to specify it as an argument to --with-ssl after
1960 Fetchmail binaries built this way support <code>ssl</code>,
1961 <code>sslkey</code>, and <code>sslcert</code> options that control
1962 SSL encryption. You will need to have an SSL-enabled mailserver
1963 to use these options. See the manual page for detals.<p>
1965 If your open OpenSSL session dies with a message that complains "PRNG
1966 not seeded", update or improve your operating system. This means that
1967 the OpenSSL library on your machine has been unable to locate a source
1968 of random bits from which to seed its random-number generator;
1969 normally these come from the <tt>/dev/urandom</tt>, and this message
1970 probably means your OS doesn't have that device.<P>.
1972 An interactive program could seed the random number generator from
1973 keystroke timings or some other form of user input. Because fetchmail
1974 is primarily designed to run forever as a background daemon, that option
1975 option is not available in this case.<P>
1978 <h2><a name="R1">R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.</a></h2>
1980 Fetchmail itself is probably working, but your SMTP port 25 listener
1981 is down or inaccessible.<p>
1983 The first thing to check is if you can telnet to port 25 on your smtp
1984 host (which is normally `localhost' unless you've specified an smtp
1985 option in your .fetchmailrc or on the command line) and get a greeting
1986 line from the listener. If the SMTP host is inaccessible or the listener
1987 is down, fix that first.<p>
1989 In Red Hat Linux 6.9, SMTP is disabled by default. To fix this,
1990 set "DAEMON=yes" in your /etc/sysconfig/sendmail file, then restart
1991 sendmail by running "/sbin/service sendmail restart".<p>
1993 If the listener seems to be up when you test with telnet, the most
1994 benign and typical problem is that the listener had a momentary seizure
1995 due to resource exhaustion while fetchmail was polling it -- process
1996 table full or some other problem that stopped the listener process
1997 from forking. If your SMTP host is not `localhost' or something else
1998 in /etc/hosts, the fetchmail glitch could also have been caused by
1999 transient nameserver failure. <p>
2001 Try running fetchmail -v again; if it succeeds, you had one of these
2002 kinds of transient glitch. You can ignore these hiccups, because a
2003 future fetchmail run will get the mail through. <p>
2005 If the listener tests up, but you have chronic failures trying to
2006 connect to it anyway, your problem is more serious. One way to work
2007 around chronic SMTP connect problems is to use --mda. But this only
2008 attacks the symptom; you may have a DNS or TCP routing problem. You
2009 should really try to figure out what's going on underneath before it
2010 bites you some other way. <p>
2012 We have one report (from toby@eskimo.com) that you can sometimes solve
2013 such problems by doing an <CODE>smtp</CODE> declaration with an IP
2014 address that your routing table maps to something other than the
2015 loopback device (he used ppp0).<p>
2017 We also have a report that this error can be caused by having an
2018 /etc/hosts file that associates your client host name with more than
2021 It's also possible that your DNS configuration isn't
2022 looking at <code>/etc/hosts</code> at all. If you're using libc5,
2023 look at <code>/etc/resolv.conf</code>; it should say something like
2029 so your <code>/etc/hosts</code> file is checked first. If you're
2030 running GNU libc6, check your <code>/etc/nsswitch.conf</code> file. Make
2031 sure it says something like
2037 again, in order to make sure <code>/etc/hosts</code> is seen first.<P>
2039 If you have a hostname set for your machine, and this hostname does
2040 not appear in /etc/hosts, you will be able to telnet to port 25 and
2041 even send a mail with rcpt to: user@host-not-in-/etc/hosts, but
2042 fetchmail can't seem to get in touch with sendmail, no matter what you
2043 set smtpaddress to.<p>
2045 We had another report from a Linux user of fetchmail 2.1 who solved his SMTP
2046 connection problem by removing the reference to -lresolv from his link
2047 line and relinking. Apparently in some older Linux distributions the
2048 libc bind library version works better.<p>
2050 As of 2.2, the configure script has been hacked so the bind library is
2051 linked only if it is actually needed. So under Linux it won't be, and
2052 this particular cause should go away.<p>
2055 <h2><a name="R2">R2. When I try to configure an MDA, fetchmail doesn't work.</a></h2>
2057 (I hear this one from people who have run into the blank-line problem in <a href="#X1">X1</a>.)<p>
2059 Try sending yourself test mail and retrieving it using the
2060 command-line options `<CODE>-k -m cat</CODE>'. This will dump exactly what
2061 fetchmail retrieves to standard output (plus the Received line
2062 fetchmail itself adds to the headers). <p>
2064 If the dump doesn't match what shows up in your mailbox when you
2065 configure an MDA, your MDA is mangling the message. If it doesn't
2066 match what you sent, then fetchmail or something on the server is
2070 <h2><a name="R3">R3. Fetchmail dumps core when given an invalid rc file.</a></h2>
2072 This is usually reported from AIX or Ultrix, but has even been known
2073 to happen on Linuxes without a recent version of <code>flex</code>
2074 installed. The problem appears to be a result of building with an
2075 archaic version of lex.<P>
2077 Workaround: fix the syntax of your .fetchmailrc file.<P>
2079 Fix: build and install the latest version of <a
2080 href="ftp://prep.ai.mit.edu/~ftp/pub/gnu">flex</a> from the Free
2081 Software Foundation. An FSF <a
2082 href="http://www.gnu.ai.mit.edu/order/ftp.html">mirror site</a>
2083 will help you get it faster.<P>
2086 <h2><a name="R4">R4. Fetchmail dumps core in -V mode, but operates normally otherwise.</a></h2>
2088 We've had this reported to us under Linux using libc-5.4.17 and gcc-2.7.2.
2089 It does not occur with libc-5.3.12 or earlier versions.<p>
2091 Workaround: link with GNU malloc rather than the stock C library malloc.<p>
2093 We're told there is some problem with the malloc() code in that
2094 version which makes it fragile in the presence of multiple free()
2095 calls on the same pointer (the malloc arena gets corrupted).
2096 Unfortunately it appears from doing gdb traces that whatever free()
2097 calls producing the problem are being made by the C library itself, not the
2098 fetchmail code (they're all from within fclose, and not an fclose called
2099 directly by fetchmail, either).<p>
2102 <h2><a name="R5">R5. Running fetchmail in daemon mode doesn't work.</a><br></h2>
2104 We have one report from a SunOS 4.1.4 user that trying to run
2105 fetchmail in detached daemon mode doesn't work, but that using the
2106 same options with -N (nodetach) is OK.<P>
2108 If this happens, you have a specific portability problem with the code
2109 in daemon.c that detaches and backgrounds the daemon fetchmail. Tell
2110 me about it so I can try to fix it. As a workaround, you can start
2111 fetchmail with -N and an ampersand to background it. A Sun user
2116 (fetchmail --nodetach <other params> &)
2119 The extra pair of parens is significant --- it makes sure that the process
2120 detaches from the initial shell (one more shell is started and dies
2121 immediately, detaching fetchmail and making it child of PID 1). This is
2122 important when you start fetchmail interactively and than quit
2123 interactive shell. The line above makes sure fetchmail lives after
2126 This should not happen under Linux or any truly POSIX-conformant Unix.<P>
2129 <h2><a name="R6">R6. Fetchmail hangs when used with pppd.</a></h2>
2131 Your problem may be with pppd's `demand' option. We have a report that
2132 fetchmail doesn't play well with it, but works with pppd if `demand'
2133 is turned off. We have no idea why this is.<p>
2136 <h2><a name="R7">R7. Fetchmail randomly dies with socket errors.</a></h2>
2138 Check the MTU value in your PPP interface reported by
2139 <code>/sbin/ifconfig</code>. If it's over 600, change it in your PPP
2140 options file. (<code>/etc/ppp/options</code> on my box). Here are
2141 option values that work:<P>
2149 <h2><a name="R8">R8. Fetchmail running as root stopped working after an OS upgrade</a></h2>
2151 In RH 6.0, the HOME value in the boot-time root environment changed
2152 from /root to / as the result of a change in init. Move your
2153 .fetchmailrc or use a -f option to explicitly point at the file.
2154 (Oddly, a similar problem has been reported from Debian systems.)<P>
2157 <h2><a name="R9">R9. Fetchmail is timing out after fetching certain
2158 messages but before deleting them</a></h2>
2160 There's a TCP/IP stalling problem under Redhat 6.0 (and possibly other
2161 recent Linuxes) that can cause this symptom. Brian Boutel writes:<p>
2164 TCP timestamps are turned on on my Linux boxes (I assume it's now the
2165 default). This uses 12 extra bytes per segment.
2166 When the tcp connection starts, the other end agrees a MSS of 1460,
2167 and then fragments 1460 byte chunks into 1448 and 12, because
2168 is is not allowing for the timestamp.<p>
2170 Then, for reasons I can't explain, it waits a long time (typically 2
2171 minutes) after the ack is sent before sending the next (fragmented)
2172 packet. Turning off tcp timestamps avoids the fragmentation and
2173 restores normal behaviour. To do this, [execute]<p>
2175 echo 0 > /proc/sys/net/ipv4/tcp_timestamps<p>
2177 I'm still unclear about the details of why this is happening. At least
2178 [now] I am now getting good performance and no queue blocking.
2182 <h2><a name="R10">R10. Fetchmail is timing out during message fetches</a></h2>
2184 This is probably a general networking issue. Sending a "RETR" command will
2185 cause the server to start sending large amounts of data, which means
2186 large packets. If your networking layer has a packet-fragmentation
2187 problem, that's where you'll see it.<p>
2190 <h2><a name="D1">D1. I think I've set up fetchmail correctly, but I'm not getting any mail.</a></h2>
2192 Maybe you have a .forward or alias set up that you've forgotten about. You
2193 should probably remove it.<p>
2195 Or maybe you're trying to run fetchmail in multidrop mode as root
2196 without a .fetchmailrc file. This doesn't do what you think it
2197 should; see question <a href="#C1">C1</a>.<p>
2199 Or you may not be connecting to the SMTP listener. Run fetchmail -v
2200 and see <a href="#R1">R1</a>.<p>
2203 <h2><a name="R11">R11. Fetchmail is dying with SIGPIPE.</a></h2>
2205 This probably means you have an <code>mda</code> option. Your MDA is
2206 croaking while being passed a message. Best fix is to remove the
2207 <code>mda</code> option and pass mail to your port 25 SMTP listener.<p>
2210 <h2><a name="D2">D2. All my mail seems to disappear after a dropped connection.</a></h2>
2212 One POP3 daemon used in the Berkeley Unix world that reports itself as
2213 POP3 version 1.004 actually throws the queue away. 1.005 fixed that.
2214 If you're running this one, upgrade immediately. (It also truncates
2215 long lines at column 1024)<P>
2217 Many POP servers, if an interruption occurs, will restore the whole
2218 mail queue after about 10 minutes. Others will restore it right
2219 away. If you have an interruption and don't see it right away, cross
2220 your fingers and wait ten minutes before retrying.<P>
2222 Some servers (such as Microsoft's NTMail) are mis-designed to restore
2223 the entire queue, including messages you have deleted. If you have
2224 one of these and it flakes out on you a lot, try setting a small
2225 <code>--fetchlimit</code> value. This will result in more IP connects
2226 to the server, but will mean it actually executes changes to the queue
2229 Qualcomm's qpopper, used at many BSD Unix sites, is better behaved.
2230 If its connection is dropped, it will first execute all DELE commands as
2231 though you had issued a QUIT (this is a technical violation of
2232 the POP3 RFCs, but a good idea in a world of flaky phone lines). Then it
2233 will re-queue any message that was being downloaded at hangup time.
2234 Still, qpopper may require a noticeable amount of time to do deletions
2235 and clean up its queue. (Fetchmail waits a bit before retrying in
2236 order to avoid a `lock busy' error.)<P>
2239 <h2><a name="D3">D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.</a></h2>
2241 Fetchmail only sends a delete mail request to the server when either
2242 (a) it gets a positive delivery acknowledgment from the SMTP
2243 listener, or (b) it gets an error 571 (the spam-filter error) from the
2244 listener. No interrupt can cause it to lose mail.<p>
2246 However, IMAP2bis has a design problem in that its normal fetch
2247 command marks a message `seen' as soon as the fetch command to get it
2248 is sent down. If for some reason the message isn't actually delivered
2249 (you take a line hit during the download, or your port 25 listener
2250 can't find enough free disk space, or you interrupt the delivery in
2251 mid-message) that `seen' message can lurk invisibly in your server
2254 Workaround: add the `<CODE>fetchall</CODE>' keyword to your fetch options.<p>
2256 Solution: switch to an <a href="http://www.imap.org">IMAP4</a> server.<p>
2259 <h2><a name="M1">M1. I've declared local names, but all my multidrop
2260 mail is going to root anyway.</a></h2>
2262 Somehow your fetchmail is never recognizing the hostname part of
2263 recipient names it parses out of To/Cc/envelope-header lines as
2264 matching the name of the mailserver machine. To check this, run
2265 fetchmail in foreground with -v -v on. You will probably see a lot of
2266 messages with the format ``line rejected, %s is not an alias of the
2267 mailserver'' or ``no address matches; forwarding to %s.'' <p>
2269 These errors usually indicate some kind of DNS configuration problem
2270 either on the server or your client machine. <p>
2272 The easiest workaround is to add a `<CODE>via</CODE>' option (if
2273 necessary) and add enough aka declarations to cover all of your
2274 mailserver's aliases, then say `<CODE>no dns</CODE>'. This will take
2275 DNS out of the picture (though it means mail may be uncollected if
2276 it's sent to an alias of the mailserver that you don't have
2279 It would be better to fix your DNS, however. DNS problems can hurt
2280 you in lots of ways, for example by making your machines
2281 intermittently or permanently unreachable to the rest of the net.<P>
2283 Occasionally these errors indicate the sort of header-parsing problem
2284 described in <a href="#M7">M7</a>.<P>
2287 <h2><a name="M2">M2. I can't seem to get fetchmail to route to a local domain properly.</a></h2>
2289 A lot of people want to use fetchmail as a poor man's internetwork
2290 mail gateway, picking up mail accumulated for a whole domain in a single
2291 server mailbox and then routing based on what's in the To/Cc/Bcc lines.<p>
2293 In general, this is not really a good idea. It would be smarter to
2294 just let the mail sit in the mailserver's queue and use fetchmail's
2295 ETRN mode to trigger SMTP sends periodically (of course, this means
2296 you have to poll more frequently than the mailserver's expiration period).
2297 If you can't arrange this, try setting up a UUCP feed.<P>
2299 If neither of these alternatives is available, multidrop mode may do
2300 (though you <em>are</em> going to get hurt by some mailing list
2301 software; see the caveats under THE USE AND ABUSE OF MULTIDROP
2302 MAILBOXES on the man page). If you want to try it, the way to do it
2303 is with the `<CODE>localdomains</CODE>' option.<p>
2305 In general, if you use localdomains you need to make sure of two other
2308 <strong>1. You've actually set up your .fetchmailrc entry to invoke multidrop mode.</strong><p>
2310 Many people set a `<CODE>localdomains</CODE>' list and then forget
2311 that fetchmail wants to see more than one name (or the wildcard `*')
2312 in a `<CODE>here</CODE>' list before it will do multidrop routing.<p>
2314 <strong>2. You may have to set `no envelope'.</strong><p>
2316 Normally, multidrop mode tries to deduce an envelope address from a message
2317 before parsing the To/Cc/Bcc lines (this enables it to avoid losing to mailing
2318 list software that doesn't put a recipient address in the To lines).<p>
2320 Some ways of accumulating a whole domain's messages in a single server
2321 mailbox mean it all ends up with a single envelope address that is
2322 useless for rerouting purposes. You may have to set `<CODE>no
2323 envelope</CODE>' to prevent fetchmail from being bamboozled by this.<p>
2325 Check also answer <a href="#T1">T1</a> on a reliable way to do multidrop
2326 delivery if your ISP (or your mail redirection provider) is using qmail.<p>
2329 <h2><a name="M3">M3. I tried to run a mailing list using multidrop, and I have a mail loop!</a></h2>
2331 This isn't fetchmail's fault. Check your mailing list. If the list
2332 expansion includes yourself or anybody else at your mailserver (that is, not on
2333 the client side) you've created a mail loop. Just chop the host part off any
2334 local addresses in the list.<p>
2336 If you use sendmail, you can check the list expansion with
2337 <CODE>sendmail -bv</CODE>.<p>
2340 <h2><a name="M4">M4. My multidrop fetchmail seems to be having DNS problems.</a></h2>
2342 We have one report from a Linux user (not the same one as in <a
2343 href="#R1">R1</a>!) who solved this problem by removing the reference
2344 to -lresolv from his link line and relinking. Apparently in some
2345 older Linux distributions the libc5 bind library version works
2348 As of 2.2, the configure script has been hacked so the bind library is linked
2349 only if it is actually needed. So under Linux it won't be, and this problem
2353 <h2><a name="M5">M5. I'm seeing long DNS delays before each message is processed.</a></h2>
2355 Use the `<CODE>aka</CODE>' option to pre-declare as many of your
2356 mailserver's DNS names as you can. When an address's host part
2357 matches an aka name, no DNS lookup needs to be done to check it.<p>
2359 If you're sure you've pre-declared all of your mailserver's DNS names,
2360 you can use the `<CODE>no dns</CODE>' option to prevent other hostname
2361 parts from being looked up at all.<p>
2363 Sometimes delays are unavoidable. Some SMTP listeners try to call DNS
2364 on the From-address hostname as a way of checking that the address is valid.<p>
2367 <h2><a name="M6">M6. How do I get multidrop mode to work with majordomo?</a></h2>
2369 In order for sendmail to execute the command strings in the majordomo
2370 alias file, it is necessary for sendmail to think that the mail it
2371 receives via SMTP really is destined for a local user name. A normal
2372 virtual-domain setup results in delivery to the default mailbox,
2373 rather than expansion through majordomo.<P>
2375 Michael <michael@bizsystems.com> gave us a recipe for dealing
2376 with this case that pairs a run control file like this:<P>
2379 poll your.pop3.server proto pop3:
2381 localdomains virtual.localdomain1.com virtual.localdomain2.com ...
2382 user yourISPusername is root * here,
2383 password yourISPpassword fetchall
2386 with a hack on your local sendmail.cf like this:<P>
2389 #############################################
2390 # virtual info, local hack for ruleset 98 #
2391 #############################################
2393 # domains to treat as direct mapped local domain
2395 CVvirtual.localdomain1.com virtual.localdomain2.com ...
2396 ---------------------------
2398 -------------------------
2399 # handle virtual users
2401 R$+ <@ $=V . > $: $1 < @ $j . >
2402 R< @ > $+ < @ $=V . > $: $1 < @ $j . >
2403 R< @ > $+ $: $1
2404 R< error : $- $+ > $* $#error $@ $1 $: $2
2405 R< $+ > $+ < @ $+ > $: $>97 $1
2408 This ruleset just strips virtual domain names off the addresses of incoming
2409 mail. Your sendmail must be 8.8 or newer for this to work. Michael
2413 I use this scheme with 2 virtual domains and the default ISP
2414 user+domain and service about 30 mail accounts + majordomo on my
2415 inside pop3 server with fetchmail and sendmail 8.83
2419 <h2><a name="M7">M7. Multidrop mode isn't parsing envelope addresses from
2420 my Received headers as it should.</a></h2>
2422 It may happen that you're getting what appear to be well-formed
2423 sendmail Received headers, but fetchmail can't seem to extract an
2424 envelope address from them. There can be a couple of reasons for
2427 <h3>Spurious Received lines need to be skipped:</h3>
2429 First, fetchmail might be looking at the wrong Received header.
2430 Normally it looks only on the first one it sees, on the theory that
2431 that one was last added and is going to be the one containing your
2432 mailserver's theory of who the message was addressed to.<P>
2434 Some (unusual) mailserver configurations will generate extra Received
2435 lines which you need to skip. To arrange this, use the optional
2436 skip prefix argument of the `envelope' option; you may need to say
2437 something like `<code>envelope 1 Received</code>' or `<code>envelope 2
2440 <h3>The `by' clause doesn't contain a mailserver alias:</h3>
2442 When fetchmail parses a Received line that looks like
2445 Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
2446 by iserv.ttns.net (8.8.5/8.8.5) with SMTP id RAA10088
2447 for <ksturgeon@fbceg.org>; Wed, 9 Sep 1998 17:01:59 -0700
2450 it checks to see if `iserv.ttns.net' is a DNS alias of your mailserver
2451 before accepting `ksturgeon@fbceg.org' as an envelope address. This
2452 check might fail if your DNS were misconfigured, or if you were using `no dns'
2453 and had failed to declare iserv.ttns.net as an alias of your server.<P>
2456 <h2><a name="M8">M8. Users are getting multiple copies of messages.</a></h2>
2458 It's a consequence of multidrop. What's happening is that you have
2459 N users subscribed to the same list. The list software sends N
2460 copies, not knowing they will end up in the same multidrop box. Since
2461 they are both locally addressed to all N users, fetchmail delivers N
2462 copies to each user.<P>
2464 Fetchmail tries to eliminate adjacent duplicate messages in a
2465 multidrop mailbox. However, this logic depends on the message-ID
2466 being identical in both copies. It also depends on the two copies
2467 being adjacent in the server mailbox. The former is usually the case,
2468 but the latter condition sometimes fails in a timing-dependent way if
2469 the server was processing multiple incoming mail streams.
2471 I could eliminate this problem by keeping a list of all message-IDs
2472 received during a poll so far and dropping any message that matches a
2473 seen mail ID. The touble is that this is an O(N**2) operation that
2474 might significantly slow down the retriweval of large mail batches.<P>
2477 <h2><a name="X1">X1. Spurious blank lines are appearing in the headers of fetched mail.</a></h2>
2479 What's probably happening is that the POP/IMAP daemon on your
2480 mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
2481 something in your delivery path (most likely an old version of the
2482 <em>deliver</em> program, which sendmail often calls to do local delivery) is
2483 failing to recognize it as a header.<p>
2485 This is not fetchmail's problem. The first thing to try is installing
2486 a current version of <em>deliver</em>. If this doesn't work, try to
2487 figure out which other program in your mail path is inserting the
2488 blank line and replace that. If you can't do either of these things,
2489 pick a different MDA (such as procmail) and declare it with the
2490 `<CODE>mda</CODE>' option.<p>
2493 <h2><a name="X2">X2. My mail client can't see a Subject line.</a></h2>
2495 First, see <a href="#X1">X1</a>. This is quite probably the same
2496 problem (X-POP3-Rcpt header or something similar being inserted by
2497 the server and choked on by an old version of <em>deliver</em>).<p>
2499 The O'Reilly sendmail book does warn that IDA sendmail doesn't process
2500 X- headers correctly. If this is your problem, all I can suggest is
2501 replacing IDA sendmail, because it's broken and not RFC822 conformant.<p>
2504 <h2><a name="X3">X3. Messages containing "From" at start of line are being split.</a></h2>
2506 If you know the messages aren't split in your server mailbox, then this
2507 is a problem with your POP/IMAP server, your client-side SMTP listener or
2508 your local delivery agent. Fetchmail cannot split messages.<p>
2510 Some POP server daemons ignore Content-Length headers and split messages on
2511 From lines. We have one report that the 2.1 version of the BSD popper
2512 program (as distributed on Solaris 2.5 and elsewhere) is broken this way.<p>
2514 You can test this. Declare an mda of `cat' and send yourself one
2515 piece of mail containing "From" at start of a line. If you see a
2516 split message, your POP/IMAP server is at fault. Upgrade to a more
2519 Sendmail and other SMTP listeners don't split RFC822 messages either.
2520 What's probably happening is either sendmail's local delivery agent or
2521 your mail reader are not quite RFC822-conformant and are breaking
2522 messages on what it thinks are Unix-style From headers. You can
2523 figure out which by looking at your client-side mailbox with vi or
2524 more. If the message is already split in your mailbox, your local
2525 delivery agent is the problem. If it's not, your mailreader is the
2528 If you can't replace the offending program, take a look at your
2529 sendmail.cf file. There will likely be a line something like<p>
2532 Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u
2535 describing your local delivery agent. Try inserting the `E' option in the
2536 flags part (the F= string). This will make sendmail turn each dangerous
2537 start-of-line From into a >From, preventing programs further downstream
2541 <h2><a name="X4">X4.</a><a name="generic_mangling">My mail is being mangled in a new and different way</a></h2>
2543 The first thing you need to do is pin down what program is doing the
2544 mangling. We don't like getting bug reports about fetchmail that are
2545 actually due to some other program's malfeasance, so please go through
2546 this diagnostic sequence before sending us a complaint.<P>
2548 There are five possible culprits to consider, listed here in the order
2549 they pass your mail:<P>
2552 <li> Programs upstream of your server mailbox.
2553 <li> The POP or IMAP server on your mailserver host.
2554 <li> The fetchmail program itself.
2555 <li> Your local sendmail.
2556 <li> Your LDA (local delivery agent), as called by sendmail or
2557 specified by <code>mda</CODE>.
2560 Often it happens that fetchmail itself is OK, but using it exposes
2561 pre-existing bugs in your downstream software, or your downstream
2562 software has a bad interaction with POP/IMAP. You need to pin down
2563 exactly where the message is being garbled in order to deduce what is
2564 actually going on.<P>
2566 The first thing to do is send yourself a test message, and retrieve it
2567 with a .fetchmailrc entry containing the following (or by running with
2568 the equivalent command-line options):<P>
2571 mda "cat >MBOX" keep fetchall
2574 This will capture what fetchmail gets from the server, except for (a)
2575 the extra Received header line fetchmail prepends, (b) header address
2576 changes due to <code>rewrite</code>, and (c) any end-of-line changes
2577 due to the <code>forcecr</code> and <code>stripcr</code> options.
2578 MBOX will in fact contain what programs downstream of fetchmail
2581 The most common causes of mangling are bugs and misconfigurations in
2582 those downstream programs. If MBOX looks unmangled, you will know
2583 that is what is going on and that it is not fetchmail's problem. Take
2584 a look at the other FAQ items in this section for possible clues about
2585 how to fix your problem.<P>
2587 If MBOX looks mangled, the next thing to do is compare it with your
2588 actual server mailbox (if possible). That's why you specified
2589 <code>keep</code>, so the server copy would not be deleted. If your
2590 server mailbox looks mangled, programs upstream of your server mailbox
2591 are at fault. Unfortunately there is probably little you can do about
2592 this aside from complaining to your site postmaster, and nothing at
2593 all fetchmail can do about it!<P>
2595 More likely you'll find that the server copy looks OK. In that case
2596 either the POP/IMAP server or fetchmail is doing the mangling. To
2597 determine which, you'll need to telnet to the server port and simulate
2598 a fetchmail session yourself. This is not actually hard (both POP3
2599 and IMAP are simple, text-only, line-oriented protocols) but requires
2600 some attention to detail. You should be able to use a fetchmail -v
2601 log as a model for a session, but remember that the "*" in your LOGIN
2602 or PASS command dump has to be replaced with your actual password.<P>
2604 The objective of manually simulating fetchmail is so you can see
2605 exactly what fetchmail sees. If you see a mangled message, then your
2606 server is at fault, and you probably need to complain to your
2607 mailserver administrators. However, we like to know what the broken
2608 servers are so we can warn people away from them. So please send
2609 us a transcript of the session including the mangling <em>and the
2610 server's initial greeting line</em>. Please tell us anything else
2611 you think might be useful about the server, like the server host's
2612 operating system.<P>
2614 If your manual fetchmail simulation shows an unmangled message,
2615 congratulations. You've found an actual fetchmail bug, which is a
2616 pretty rare thing these days. Complain to us and we'll fix it.
2617 Please include the session transcript of your manual fetchmail
2618 simulation along with the other things described in the FAQ entry on
2619 <a href="#G3">reporting bugs</a>.
2622 <h2><a name="X5">X5. Using POP3, retrievals seems to be fetching too much!</a></h2>
2624 This may happen in versions of fetchmail after 4.4.1 and before 4.4.8.
2625 Versions after 4.4.1 use POP3's TOP command rather than RETR, in order
2626 to avoid marking the message seen (leaving it unseen is helpful for
2627 later recovery if you lose your connection in the middle of a
2630 Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction
2631 with Eudora qpopper versions 2.3 and later. The TOP bounds check was
2632 fooled by an overflow condition in the TOP argument. Decrementing the
2633 TOP argument in 4.4.7 fixed this.<P>
2635 Fix: Upgrade to a later version of fetchmail.<P>
2637 Workaround: set the <code>fetchall</code> option. Under POP3
2638 this has the side effect of forcing RETR use.<P>
2641 <h2><a name="X6">X6. My mail attachments are being dropped or mangled.</a></h2>
2643 This isn't fetchmail's doing -- fetchmail never drops lines in message
2644 bodies or attachments. It may be your POP server, or it may be the
2645 sender's mail user agent (or a bad combination of both).<p>
2647 The Mail Max POP3 server and the InterChange and Imail IMAP servers
2648 are known to simply drop MIME attachments when uploading messages.
2649 We've had sporadic reports of problems with Microsoft Exchange and
2650 Outlook servers. Windows- and NT-based POP servers seem especially
2651 prone to mangle attachments. If you are running one of these,
2652 replacing your server with a Unix machine is probably the only
2653 effective solution.<p>
2655 We've also had a report that Lotus Notes sometimes trashes the
2656 MIME type of messages. In particular, it seems to modify MIME
2657 headers introducing type application/pdf, mangling the type
2658 to application/octet-stream. It may corrupt other MIME types
2661 The IMAP service of Lotus Domino has a known bug in the way it
2662 generates MIME Content-type headers (observed on Lotus Domino 5.0.2b).
2663 It's a subtle one that doesn't show up when Netscape Messenger and
2664 other clients use a FETCH BODY[] to grab the whole message. When
2665 fetchmail uses FETCH RFC822.HEADER and FETCH RFC822.TEXT to get first
2666 the header and then the body, Domino generates different Boundary tags
2667 for each part, .e.g. one tag is declared in the Content-type header and
2668 another is used to separate the MIME parts in the body. This doesn't
2669 work. (I have heard a rumor that this bug is scheduled to be fixed
2670 in Domino release 6; you can find a workaround at contrib/domino.)<p>
2672 Another rich source of attachment problems is Microsoft Exchange and
2673 Microsoft Outlook. If you see unreadable attachments with a
2674 ContentType of "application/x-tnef", you're having this problem. The
2675 <a href="http://world.std.com/~damned/software.html">TNEF</a> utility
2678 Rob Funk explains: Unfortunately there also remain many mail user
2679 agents that don't write correct MIME messages. One big offender is Sun
2680 MailTool attachments, which are formatted enough like MIME that some
2681 programs could get confused; these are generated by the mailtool and
2682 dtmail programs (the mail programs in Sun's OpenWindows and CDE
2685 One solution to problems related to misformatted MIME attachments is
2686 the <a href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/">emil</a>
2688 href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/TUTORIAL.html">tutorial</a>
2689 file at that site for details on emil. It is useful for
2690 converting character sets, attachment encodings, and attachment
2691 formats. At this writing, emil does not appear to have been
2692 maintained since a patch to version 2.1.0beta9 in late 1997, but it is
2695 One good way of using emil is from within procmail. You can have
2696 procmail look for signs of problematic message formatting, and pipe
2697 those messages through emil to be fixed. emil will not always be able
2698 to fix the problem, in which case the message is unchanged.<p>
2700 A possible rule to be inserted into a .procmailrc file for using emil
2705 * 1^1 ^Content-Type: \/X-sun[^;]*
2706 * 1^1 ^Content-Type: \/application/mac-binhex[^;]*
2707 * 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]*
2708 * 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]*
2710 LOG="Converting $MATCH
2713 | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME \
2714 | gawk '{gsub(/\r\n?/,"\n");print $0}'
2718 The "1^1" in the conditions is a way of specifying to procmail that if
2719 any one of the four listed expressions is found in the message, the
2720 total condition is considered true, and the message gets passed into
2721 emil. These four subconditions check whether the message has a Sun
2722 attachment, a binhex attachment, or a uuencoded attachment; there are
2723 others that could be added to check these things better and to check
2724 other relevant conditions. The "LOG=" line writes a line into the
2725 procmail log; the lone double-quote beginning the following line makes
2726 sure the log entry gets an end-of-line character. The call to gawk
2727 (GNU awk) is for fixing end-of-line conventions, since emil sometimes
2728 leaves those in the format of the originating machine; it could
2729 probably be replaced with a sed subsitution.<p>
2731 The emil call itself tries to ensure that the message uses:
2733 <li> BinHex encoding for any Apple Macintosh-only attachments
2734 <li> Quoted-Printable encoding for text (when necessary)
2735 <li> Base64 Encoding for binary attachments
2736 <li> iso-8859-1 character set for text (unfortunately emil can't yet
2737 convert from windows-1252 to iso-8859-1)
2738 <li> Quoted-Printable encoding for headers
2739 <li> MIME attachment format
2742 Most of these (the primary exceptions being the character set and the
2743 Apple binary format) are as they should be for good internet
2744 interoperability.<p>
2746 Some mail servers (Lotus Domino is a suspect here) mangle
2747 Sun-formatted messages, so the conversion to MIME needs to happen
2748 before such programs see the message. The ideal is to rid the world
2749 of Sun-formatted messages: don't use mailtool for sending attachments
2750 (it doesn't understand MIME anyway, and most of the world doesn't
2751 understand its attachments, so it really shouldn't be used at all),
2752 and make sure dtmail is set to use MIME rather than mailtool's format.<p>
2755 <h2><a name="X7">X7. Some mail attachments are hanging fetchmail.</a></h2>
2757 This isn't fetchmail's problem either; fetchmail doesn't know anything
2758 about mail attachments and doesn't treat them any differently from
2759 plain message data.<P>
2761 The most usual cause of this problem seems to be bugs in your network
2762 transport layer's capability to handle the very large TCP/IP packets
2763 that attachments tend to turn into. You can test this theory by trying to
2764 download the offending message through a webmail account; using HTTP
2765 for the message tends to simulate large-packet stress rather well, and
2766 you will probably find that the messages that seem to be choking
2767 fetchmail will make your HTTP download speed drop to zero.<P>
2769 This problem can be caused by subtle bugs in the packet-reassembly
2770 layer of your TCP/IP stack; these often don't manifest at normal
2771 packet sizes. It may also be caused by malfunctioning path-MTU
2772 discovery on the mailserver. Or, if there's a modem in the link,
2773 it may be because the attachment contains the Hayes mode escape "+++".
2776 <h2><a name="O1">O1. The --logfile option doesn't work if the logfile doesn't exist.</a></h2>
2778 This is a feature, not a bug. It's in line with normal practice for
2779 system daemons and allows you to suppress logging by removing the log,
2780 without hacking potentially fragile startup scripts. To get around
2781 it, just touch(1) the logfile before you run fetchmail (this will have
2782 no effect on the contents of the logfile if it already exists).<P>
2785 <h2><a name="O2">O2. Every time I get a POP or IMAP message the header
2786 is dumped to all my terminal sessions.</a></h2>
2788 Fetchmail uses the local sendmail to perform final delivery, which
2789 Netscape and other clients doesn't do; the announcement of new messages
2790 is done by a daemon that sendmail pokes. There should be a ``biff''
2791 command to control this. Type
2797 to turn it off. If this doesn't work, try the command
2803 which is essentially what <code>biff -n</code> will do. If this
2804 doesn't work, comment out any reference to ``comsat'' in your
2805 /etc/inetd.conf file and restart inetd.<P>
2807 In Slackware Linux distributions, the last line in /etc/profile is
2819 to solve the problem system-wide.<P>
2822 <h2><a name="O3">O3. Does fetchmail reread its rc file every poll cycle?</a></h2>
2824 No, but versions 5.2.2 and later will notice when you modify your rc
2825 file and restart, reading it.
2828 <h2><a name="O4">O4. Why do deleted messages show up again when I take
2829 a line hit while downloading?</a></h2>
2831 Because you're using a POP3 other than Qualcomm qpopper, or an IMAP
2832 with a long expunge interval.<P>
2834 According to the POP3 RFCs, deletes aren't actually performed until
2835 you issue the end-of-session QUIT command. Fetchmail cannot fix this,
2836 because doing it right takes cooperation from the server. There are
2837 two possible remedies:<P>
2839 One is to switch to qpopper (the free POP3 server from Qualcomm,
2840 the Eudora people). The qpopper software violates the POP3 RFCs by
2841 doing an expunge (removing deleted messages) on a line hangup, as well
2842 as on processing a QUIT command.<P>
2844 The other (which we recommend) is to switch to <a
2845 href="http://www.imap.org">IMAP</a>. IMAP has an explicit expunge
2846 command and fetchmail normally uses it to delete messages immediately
2847 after they are downloaded.<P>
2849 If you get very unlucky, you might take a line hit in the window
2850 between the delete and the expunge. If you've set a longer expunge
2851 interval, the window gets wider. This problem should correct itself
2852 the next time you complete a successful query.<P>
2855 <h2><a name="O5">O5. Why is fetched mail being logged with my name, not the real From address?</a></h2>
2857 Because logging is done based on the address indicated by the sending
2858 SMTP's MAIL FROM, and some listeners are picky about that address.<p>
2860 Some SMTP listeners get upset if you try to hand them a MAIL FROM
2861 address naming a different host than the originating site for your
2862 connection. This is a feature, not a bug -- it's supposed to help
2863 prevent people from forging mail with a bogus origin site. (RFC 1123
2864 says you shouldn't do this exclusion...)<p>
2866 Since the originating site of a fetchmail delivery connection is
2867 localhost, this effectively means these picky listeners will barf on
2868 any MAIL FROM address fetchmail hands them with an @ in it!<p>
2870 Versions 2.1 and up try the header From address first and fall back to
2871 the calling-user ID. So if your SMTP listener isn't picky, the log
2875 <h2><a name="O6">O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.</a></h2>
2877 Sendmail does a hostname lookup when it first starts up, and also each
2878 time it gets a HELO in listener mode.<p>
2880 Your resolver configuration may be causing one of these lookups to
2881 fail and time out. Check <code>/etc/resolv.conf</code> and
2882 <code>/etc/hosts</code> file. Make sure your hostname and
2883 fully-qualified domain name are both in <code>/etc/hosts</code>, and
2884 that hosts is looked at before DNS is queried. You probably also want
2885 your remote mail server(s) to be in the hosts file.<p>
2887 You can suppress the startup-time lookup if need to by reconfiguring
2888 with <code>FEATURE(nodns)</code>.<p>
2890 Configuring your bind library to cache DNS lookups locally may help,
2891 and is a good idea for speeding up other services as well. Switching to
2892 a faster MTA like qmail or exim might help. <p>
2895 <h2><a name="O7">O7. Why doesn't fetchmail deliver mail in date-sorted order?</a></h2>
2897 Because that's not the order the server hands it to fetchmail in.<P>
2899 Fetchmail getting mail from a POP server delivers mail in the order
2900 that your server delivers mail. Fetchmail can't do anything about
2901 this; it's a limitation of the underlying POP protocol.<P>
2903 In theory it might be possible for fetchmail in IMAP mode to sort
2904 messages by date, but this would be in violation of two basics of
2905 fetchmail's design philosophy: (a) to be as simple and transparent a
2906 pipe as possible, and (b) to <em>hide</em>, rather than emphasize, the
2907 differences between the remote-fetch protocols it uses.<P>
2909 Re-ordering messages is a user-agent function, anyway.<P>
2912 <h2><a name="O8">O8. I'm using pppd. Why isn't my monitor option working?</a></h2>
2914 There is a combination of circumstances that can confuse fetchmail.
2915 If you have set up demand dialing with pppd, and pppd has an idle
2916 timeout, and you have lcp-echo-interval set, then the
2917 lcp-echo-interval time must be longer than the pppd idle timeout.
2918 Otherwise it is going keep increasing the packet counters that fetchmail
2919 relies upon, triggering fetchmail into polling after its own delay
2920 interval and thus preventing the pppd link from ever reaching its
2921 inactivity timeout.<p>
2924 <h2><a name="O9">O9. Why does fetchmail keep retrieving the same messages
2925 over and over?</a></h2>
2927 First, check to see that you haven't enabled the <cite>keep</cite>
2928 and <cite>fetchall</cite> option. If you have, turn <cite>keep</cite> off.<p>
2930 There are various forms of lossage involving the POP3 UIDL feature
2931 that can lead to all your old messages being seen again after a line
2932 drop. I have given up trying to fix these, as the UIDL code breaks
2933 worse every time I touch it. The problem is fundamental; maintaining
2934 and garbage-collecting the right kind of client-side state is just
2935 hard. Whoever put UIDLs in RFC1725 and removed LAST should be hung
2936 up by his thumbs and whipped with scorpions. The right answers are
2937 either (a) live with the occasional breakage, (b) switch to IMAP4,
2938 or (c) fix the code yourself and send me a patch. Unless you choose
2939 (c), I don't want to hear about it.<p>
2941 This can also happen when some other mail client is logged in to your
2942 mail server, if it uses a simple exclusive-locking scheme (and many,
2943 especially most POP3 servers, do exactly that). Your fetchmail is
2944 able to retrieve the messages, but because the mailbox is write-locked
2945 by the other instance yours can neither mark messages seen or delete them.
2946 The solution is to either (a) wait for the other client to finish, or (b)
2949 James Stevens <James.Stevens@kyzo.com> writes:<p>
2952 We had a Linux box dialing the Net and collecting mail from an NT POP3
2953 server. Fetchmail was correctly collecting and deleting each e-mail
2954 one by one. However,the dial-up connection was very unreliable and
2955 would often just drop out in the middle of a session.<p>
2957 Interestingly, unless the TCP POP3 connection was terminated normally
2958 (I guess with a POP3 "QUIT" command) NT would then roll back all the
2961 This meant if the first e-mail was very large it might just end up
2962 continuously collecting it, basically jamming the queue. Or, if the
2963 queue became very full itmight never get a long enough phone
2964 connection to retrieve the entire mailbox, and NT would roll back any
2965 deletes, so it would end up collecting (and delivering) the first few
2966 e-mails again and again. As the POP3 mailbox became fuller and fuller
2967 the chances of getting a connection long enough to collect theentire
2968 mailbox became smaller and smaller.<p>
2970 Our solution was to make fetchmail only collect a few (say 5 or 10)
2971 e-mails at atime, thus trying to ensure that the POP3 connection is
2972 terminated correctly.
2975 That's one solution. Perhaps a better one would be to FORMAT C: and
2976 install Linux on your server...<p>
2979 <table width="100%" cellpadding=0><tr>
2980 <td width="30%">Back to <a href="index.html">Fetchmail Home Page</a>
2981 <td width="30%" align=center>To <a href="/~esr/sitemap.html">Site Map</a>
2982 <td width="30%" align=right>$Date: 2000/12/12 03:53:25 $
2985 <P><ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS>
2990 compile-command: "(cd ~/WWW; upload fetchmail/fetchmail-FAQ.html)"