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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>
57 <h1>Configuration questions:</h1>
59 <a href="#C1">C1. Why do I need a .fetchmailrc when running as root on my own machine?</a><br>
60 <a href="#C2">C2. How can I arrange for a fetchmail daemon to get killed when I log out?</a><br>
61 <a href="#C3">C3. How do I know what interface and address to use with --interface?</a><br>
62 <a href="#C4">C4. How can I set up support for sendmail's anti-spam features?</a><br>
63 <a href="#C5">C5. How can I poll some of my mailboxes more/less often than others?</a><br>
64 <a href="#C6">C6. Fetchmail works OK started up manually, but not from an init script.</a><br>
65 <a href="#C7">C7. How can I forward mail to another host?.</a><br>
67 <h1>How to make fetchmail play nice with various MTAs:</h1>
69 <a href="#T1">T1. How can I use fetchmail with sendmail?</a><br>
70 <a href="#T2">T2. How can I use fetchmail with qmail?</a><br>
71 <a href="#T3">T3. How can I use fetchmail with exim?</a><br>
72 <a href="#T4">T4. How can I use fetchmail with smail?</a><br>
73 <a href="#T5">T5. How can I use fetchmail with SCO's MMDF?</a><br>
74 <a href="#T6">T6. How can I use fetchmail with Lotus Notes?</a><br>
76 <h1>How to make fetchmail work with various servers:</h1>
78 <a href="#S1">S1. How can I use fetchmail with qpopper?</a><br>
79 <a href="#S2">S2. How can I use fetchmail with Microsoft Exchange?</a><br>
80 <a href="#S3">S3. How can I use fetchmail with Compuserve RPA?</a><br>
81 <a href="#S4">S4. How can I use fetchmail with Demon Internet's SDPS?</a><br>
82 <a href="#S5">S5. How can I use fetchmail with usa.net's servers?</a><br>
83 <a href="#S6">S6. How can I use fetchmail with HP OpenMail?</a><br>
84 <a href="#S7">S7. How can I use fetchmail with geocities POP3 servers?</a><br>
85 <a href="#S8">S8. How can I use fetchmail with Hotmail?</a><br>
86 <a href="#S9">S9. How can I use fetchmail with MSN?</a><br>
87 <a href="#S10">S10. How can I use fetchmail with SpryNet?</a><br>
88 <a href="#S11">S11. How can I use fetchmail with FTGate?</a><br>
89 <a href="#S12">S12. How can I use fetchmail with MailMax?</a><br>
90 <a href="#S13">S13. How can I use fetchmail with Novell GroupWise?</a><br>
91 <a href="#S14">S14. How can I use fetchmail with InterChange?</a><br>
93 <h1>How to set up well-known security and authentication methods:</h1>
95 <a href="#K1">K1. How can I use fetchmail with SOCKS?</a><br>
96 <a href="#K2">K2. How can I use fetchmail with IPv6 and IPsec?</a><br>
97 <a href="#K3">K3. How can I get fetchmail to work with ssh?</a><br>
98 <a href="#K4">K4. What do I have to do to use the IMAP-GSS protocol?</a><br>
99 <a href="#K5">K5. How can I use fetchmail with SSL?</a><br>
101 <h1>Runtime fatal errors:</h1>
103 <a href="#R1">R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.</a><br>
104 <a href="#R2">R2. When I try to configure an MDA, fetchmail doesn't work.</a><br>
105 <a href="#R3">R3. Fetchmail dumps core when given an invalid rc file.</a><br>
106 <a href="#R4">R4. Fetchmail dumps core in -V mode, but operates normally otherwise.</a><br>
107 <a href="#R5">R5. Running fetchmail in daemon mode doesn't work.</a><br>
108 <a href="#R6">R6. Fetchmail hangs when used with pppd.</a><br>
109 <a href="#R7">R7. Fetchmail randomly dies with socket errors.</a><br>
110 <a href="#R8">R8. Fetchmail running as root stopped working after an OS upgrade</a><br>
111 <a href="#R9">R9. Fetchmail is timing out after fetching certain
112 messages but before deleting them</a><br>
113 <a href="#R10">R10. Fetchmail is timing out during message fetches</a></br>
115 <h1>Disappearing mail</h1>
117 <a href="#D1">D1. I think I've set up fetchmail correctly, but I'm not getting any mail.</a><br>
118 <a href="#D2">D2. All my mail seems to disappear after a dropped connection.</a><br>
119 <a href="#D3">D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.</a><br>
121 <h1>Multidrop-mode problems:</h1>
123 <a href="#M1">M1. I've declared local names, but all my multidrop mail is going to root anyway.</a><br>
124 <a href="#M2">M2. I can't seem to get fetchmail to route to a local domain properly.</a><br>
125 <a href="#M3">M3. I tried to run a mailing list using multidrop, and I have a mail loop!</a><br>
126 <a href="#M4">M4. My multidrop fetchmail seems to be having DNS problems.</a><br>
127 <a href="#M5">M5. I'm seeing long DNS delays before each message is processed.</a><br>
128 <a href="#M6">M6. How do I get multidrop mode to work with majordomo?</a><br>
129 <a href="#M7">M7. Multidrop mode isn't parsing envelope addresses from
130 my Received headers as it should.</a><br>
131 <a href="#M8">M8. Users are getting multiple copies of messages.</a><br>
133 <h1>Mangled mail:</h1>
135 <a href="#X1">X1. Spurious blank lines are appearing in the headers of fetched mail.</a><br>
136 <a href="#X2">X2. My mail client can't see a Subject line.</a><br>
137 <a href="#X3">X3. Messages containing "From" at start of line are being split.</a><br>
138 <a href="#X4">X4. My mail is being mangled in a new and different way.</a><br>
139 <a href="#X5">X5. Using POP3, retrievals seems to be fetching too much!</a><br>
140 <a href="#X6">X6. My mail attachments are being dropped or mangled.</a><br>
142 <h1>Other problems:</h1>
144 <a href="#O1">O1. The --logfile option doesn't work if the logfile doesn't exist.</a><br>
145 <a href="#O2">O2. Every time I get a POP or IMAP message the header is
146 dumped to all my terminal sessions.</a><br>
147 <a href="#O3">O3. Does fetchmail reread its rc file every poll cycle?</a><br>
148 <a href="#O4">O4. Why do deleted messages show up again when I take
149 a line hit while downloading?</a><br>
150 <a href="#O5">O5. Why is fetched mail being logged with my name, not the real From address?</a><br>
151 <a href="#O6">O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.</a><br>
152 <a href="#O7">O7. Why doesn't fetchmail deliver mail in date-sorted order?</a><br>
153 <a href="#O8">O8. I'm using pppd. Why isn't my monitor option working?</a><br>
154 <a href="#O9">O9. Why does fetchmail keep retrieving the same messages
155 over and over?</a><br>
159 <h2><a name="G1">G1. What is fetchmail and why should I bother?</a></h2>
161 Fetchmail is a one-stop solution to the remote mail retrieval problem
162 for Unix machines, quite useful to anyone with an intermittent PPP or
163 SLIP connection to a remote mailserver. It can collect mail using any
164 variant of POP or IMAP and forwards via port 25 to the local SMTP
165 listener, enabling all the normal forwarding/filtering/aliasing
166 mechanisms that would apply to local mail or mail arriving via a
167 full-time TCP/IP connection.<p>
169 Fetchmail is not a toy or a coder's learning exercise, but an
170 industrial-strength tool capable of transparently handling every
171 retrieval demand from those of a simple single-user ISP connection up
172 to mail retrieval and rerouting for an entire client domain.
173 Fetchmail is easy to configure, unobtrusive in operation, powerful,
174 feature-rich, and well documented. <P>
176 Fetchmail is <a href="http://www.opensource.org">Open Source</a>
177 software. The openness of the sources is the strongest assurance of
178 quality you can have. Extensive peer review by a large,
179 multi-platform user community has shown that fetchmail is as near
180 bulletproof as the underlying protocols permit.<p>
182 Fetchmail is licensed under the <a
183 href="http://gnu.org//copyleft/gpl.html">GNU General Public
186 If you found this FAQ in the distribution, see the README for fetchmail's
187 full feature list.<p>
190 <h2><a name="G2">G2. Where do I find the latest FAQ and fetchmail
193 The latest HTML FAQ is available alongside the latest fetchmail
194 sources at the fetchmail home page:
195 <a href="http://www.tuxedo.org/~esr/fetchmail">
196 http://www.tuxedo.org/~esr/fetchmail</a>. You can also usually find
198 href="http://sunsite.unc.edu/pub/Linux/system/mail/pop/!INDEX.html">POP
199 mail tools directory on Sunsite</a>.<p>
201 A text dump of this FAQ is included in the fetchmail
202 distribution. Because it freezes at distribution release time, it may
203 not be completely current.<p>
206 <h2><a name="G3">G3. I think I've found a bug. Will you fix it?</a></h2>
208 Yes I will, provided you include enough diagnostic information for me
209 to go on. Send bugs to <a
210 href="mailto:fetchmail-friends@ccil.org">fetchmail-friends</a>. When reporting
211 bugs, please include the following:
214 <li>Your operating system and compiler version.
215 <li>A copy of your POP or IMAP server's greeting line.
216 <li>The name and version of the SMTP listener or MDA you are forwarding to.
217 <li>Any command-line options you used.
218 <li>The output of fetchmail -V called with whatever other
219 command-line options you used.
222 If you have FTP access to your remote mail account, and you have any
223 suspicion that the bug was triggered by a particular message, please
224 include a copy of the message that triggered the bug.<p>
226 Often, the first thing I will do when you report a bug is tell you to
227 upgrade to the newest version of fetchmail, and then see if the
228 problem reproduces. So you'll probably save us both time if you
229 upgrade and test with the latest version <em>before</em> sending in a
232 It is helpful if you include your .fetchmailrc file, but not necessary
233 unless your symptom seems to involve an error in configuration
234 parsing. If you do send in your .fetchmailrc, mask the passwords
237 If fetchmail seems to run and fetch mail, but the headers look mangled
238 (that is, headers are missing or blank lines are inserted in the
239 headers) then read the FAQ items in section <a href="#X1">X</a>
240 before submitting a bug report. Pay special attention to the item on
241 <a href="#generic_mangling">diagnosing mail mangling</a>. There are
242 lots of ways for other programs in the mail chain to screw up that
243 look like fetchmail's fault, but you may be able to fix these by
244 tweaking your configuration.<P>
246 A transcript of the failed session with -v -v (yes, that's
247 <em>two</em> -v options, enabling debug mode) will almost always be useful.
248 It is very important that the transcript include your POP/IMAP server's
249 greeting line, so I can identify it in case of server problems. This
250 transcript will not reveal your passwords, which are specially masked
251 out precisely so the transcript can be passed around.<P>
253 If the bug involves a core dump or hang, a gdb stack trace is good to have.
254 (Bear in mind that you can attach gdb to a running but hung process by
255 giving the process ID as a second argument.) You will need to
259 CFLAGS=-g LDFLAGS=" " ./configure
262 and then rebuild in order to generate a version that can be gdb-traced.<p>
264 Best of all is a mail file which, when fetched, will reproduce the
265 bug under the latest (current) version.<p>
267 Any bug I can reproduce will usually get fixed very quickly, often
268 within 48 hours. Bugs I can't reproduce are a crapshoot. If the
269 solution isn't obvious when I first look, it may evade me for a long
270 time (or to put it another way, fetchmail is well enough tested that the
271 easy bugs have long since been found). So if you want your bug fixed
272 rapidly, it is not just sufficient but nearly <em>necessary</em> that
273 you give me a way to reproduce it.<p>
276 <h2><a name="G4">G4. I have this idea for a neat feature. Will you add it?</a></h2>
278 Probably not. Most of the feature suggestions I get are for ways to
279 set various kinds of administrative policy or add more spam filtering
280 (the most common one, which I used to get about four million times a week
281 and got <em>really</em> tired of, is for tin-like kill files).<p>
283 You can do spam filtering better with procmail or maildrop on the
284 server side and (if you're the server sysadmin) sendmail.cf domain
285 exclusions. You can do other policy things better with the
286 <CODE>mda</CODE> option and script wrappers around fetchmail. If
287 it's a prime-time-vs.-non-prime-time issue, ask yourself whether a
288 wrapper script called from crontab would do the job.<p>
290 I'm not going to do these; fetchmail's job is transport, not policy, and I
291 refuse to change it from doing one thing well to attempting many things badly.
292 One of my objectives is to keep fetchmail simple so it stays reliable.<p>
294 For reasons fetchmail doesn't have other commonly-requested features
295 (such as password encryption, or multiple concurrent polls from the
296 same instance of fetchmail) see the <a
297 href="http://www.tuxedo.org/fetchmail/design.notes.html">design notes</a>.<p>
299 Fetchmail is a mature project, no longer in constant active
300 development. It is no longer my top project, and I am going to be
301 quite reluctant to add features that might either jeopardize its
302 stability or involve me in large amounts of coding.<p>
304 All that said, if you have a feature idea that really is about a transport
305 problem that can't be handled anywhere but fetchmail, lay it on me. I'm
306 very accommodating about good ideas.<p>
309 <h2><a name="G5">G5. Is there a mailing list for exchanging tips?</a></h2>
311 There is a fetchmail-friends list for people who want to discuss fixes
312 and improvements in fetchmail and help co-develop it. It's at <a
313 href="mailto:fetchmail-friends@thyrsus.com">fetchmail-friends@thyrsus.com</a>.
314 There is also an announcements-only list, <em>fetchmail-announce@thyrsus.com</em>.<P>
316 Both lists are SmartList reflectors; sign up in the usual way with a
317 message containing the word "subscribe" in the subject line sent to
318 <a href="mailto:fetchmail-friends-request@thyrsus.com?subject=subscribe">
319 fetchmail-friends-request@thyrsus.com</a> or
320 <a href="mailto:fetchmail-announce-request@thyrsus.com?subject=subscribe">
321 fetchmail-announce-request@thyrsus.com</a>. (Similarly, "unsubscribe"
322 in the Subject line unsubscribes you, and "help" returns general list help) <p>
325 <h2><a name="G6">G6. So, what's this I hear about a fetchmail paper?</a></h2>
327 The fetchmail development was also a sociological experiment, an
328 extended test to see if my theory about the critical features of the
329 Linux development model is correct.<p>
331 The experiment was a success. I wrote a paper about it titled <a
332 href="http://www.tuxedo.org/~esr/writings/cathedral.html">The
333 Cathedral and the Bazaar</a> which was first presented at Linux
334 Kongress '97 in Bavaria and very well received there. It was also
335 given at Atlanta Linux Expo, Linux Pro '97 in Warsaw, and the first
336 Perl Conference, at UniForum '98, and was the basis of an invited
337 presentation at Usenix '98. The folks at Netscape tell me it helped
339 href="http://www.netscape.com/newsref/pr/newsrelease558.html"> give
340 away the source for Netscape Communicator</a>.<p>
342 If you're reading a non-HTML dump of this FAQ, you can find the paper
343 on the Web with a search for that title.<p>
346 <h2><a name="G7">G7. What is the best server to use with fetchmail?</a></h2>
348 The short answer: IMAP4rev1 running over Unix.<P>
350 Here's a longer answer: <P>
352 Fetchmail will work with any POP, IMAP, or ESMTP/ETRN server that
353 conforms to the relevant RFCs (and even some outright broken ones like
354 <a href="#S2">Microsoft Exchange</a> and <a href="#S12">Novell
355 GroupWise</a>). This doesn't mean it works equally well with all,
356 however. POP2 servers, and POP3 servers without LAST, limit
357 fetchmail's capabilities in various ways described on the manual
360 Most modern Unixes (and effectively all Linux/*BSD systems) come with
361 POP3 support preconfigured (but beware of the horribly broken POP3
362 server mentioned in <a href="#D2">D2</a>). An increasing minority
363 also feature IMAP (you can detect IMAP support by running fetchmail in
364 AUTO mode, or by using the `Probe for supported protocols' function in
365 the fetchmailconf utility).<P>
367 If you have the option, we recommend using or installing an IMAP4rev1
368 server; it has the best facilities for tracking message `seen' states.
369 It also recovers from interrupted connections more gracefully than
370 POP3, and enables some significant performance optimizations.<P>
372 Don't be fooled by NT/Exchange propaganda. M$ Exchange is just plain
373 broken (see item <a href="#S2">S2</a>) and NT cannot handle the
374 sustained load of a high-volume remote mail server. Even Microsoft
375 itself knows better than to try this; their own Hotmail service runs
376 over Solaris! For extended discussion, see John Kirch's excellent <a
377 href="http://unix-vs-nt.org/kirch/">white paper</a> on Unix
378 vs. NT performance.<P>
380 You can find sources for IMAP software at <a
381 href="http://www.imap.org">The IMAP Connection</a>; we like the
382 open-source <a href="ftp://ftp.cac.washington.edu/imap/">UW IMAP</a>
383 server, which is the reference implementation of IMAP. UW IMAP's
384 support for GSSAPI gives you a good way to authenticate without
385 sending a password en clair.<P>
387 Source for a high-quality supported implementation of POP is available
388 from the <a href="ftp://ftp.qualcomm.com/eudora/servers/unix/popper/">Eudora
389 FTP site</a>. Don't use 2.5, which has a rather restrictive license.
390 The 2.5.2 version appears to restore the open-source license of
391 previous versions.<P>
394 <h2><a name="G8">G8. What is the best mail program to use with fetchmail?</a></h2>
396 Fetchmail will work with all popular <a href="#T1">mail transport programs</a>.
397 It also doesn't care which user agent you use, and user agents are as a
398 rule almost equally indifferent to how mail is delivered into your system
399 mailbox. So any of the popular Unix mail agents --
400 <a href="http://www.myxa.com/old/elm.html">elm</a>,
401 <a href="http://www.washington.edu/pine/">pine</a>
402 <a href="http://www.cs.indiana.edu/docproject/mail/mh.html">mh</a>,
403 or <a href="http://www.mutt.org">mutt</a>
404 -- will work fine with fetchmail.<p>
406 All this having been said, I can't resist putting in a discreet plug
407 for <a href="http://www.mutt.org">mutt</a>. My own personal mail
408 setup is sendmail plus fetchmail plus mutt. Mutt's interface is only
409 a little different from that of its now-moribund ancestor elm, but its
410 excellent handling of MIME and PGP put it in a class by itself. You
411 won't need its built-in POP3 support, though; most of the mutt
412 developers will cheerfully admit that fetchmail's is better :-).<p>
415 <h2><a name="G9">G9. How can I avoid sending my password en clair?</a></h2>
417 Depending on what your mail server you are talking to, this ranges
418 from trivial to impossible. It may even be next to useless.<P>
420 Most people use fetchmail over phone wires, which are hard to tap.
421 Anybody with the skill and resources to do this could get into your
422 server mailbox with much less effort by subverting the server host.
423 So if your provider setup is modem wires going straight into a service
424 box, you probably don't need to worry.<P>
426 In general there is little point in trying to secure your fetchmail
427 transaction unless you trust the security of the server host you are
428 retrieving mail from. Your vulnerability is more likely to be an
429 insecure local network on the server end (e.g. to somebody with a TCP/IP
430 packet sniffer intercepting Ethernet traffic between the modem
431 concentrator you dial in to and the mailserver host).<P>
433 Having realized this, you need to ask whether password encryption
434 alone will really address your security exposure. If you think you
435 might be snooped between server and client, it's better to use
436 end-to-end encryption on your whole mail stream so none of it can be
437 read. One of the advantages of fetchmail over conventional SMTP-push
438 delivery is that you may be able to arrange this by using ssh(1); see
439 <a href="#K3">K3</a>.<P>
441 Note that ssh is not a complete privacy solution either, as your mail
442 could have been snooped in transit to your POP server from wherever it
443 originated. For best security, agree with your correspondents to use
444 a tool such as <a href="http://www.gnupg.org/">GPG</a> (Gnu Privacy
445 Guard) or PGP (Pretty Good Privacy).<P>
447 If ssh/sshd isn't available, or you find it too complicated for you to
448 set up, password encryption will at least keep a malicious cracker
449 from deleting your mail, and require him to either tap your connection
450 continuously or crack root on the server in order to read it.<P>
452 You can deduce what encryptions your mail server has available
453 by looking at the server greeting line (and, for IMAP, the
454 response to a CAPABILITY query). Do a <code>fetchmail -v</code>
455 to see these, or telnet direct to the server port (110 for POP3, 143 for
458 The facility you are most likely to have available is APOP. This is a
459 POP3 feature supported by many servers (fetchmailconf's autoprobe
460 facility will detect it and tell you if you have it). If you see
461 something in the greeting line that looks like an
462 angle-bracket-enclosed Internet address with a numeric left-hand part,
463 that's an APOP challenge (it will vary each time you log in). You can
464 register a secret on the host (using <code>popauth(8)</code> or some
465 program like it). Specify the secret as your password in your
466 .fetchmailrc; it will be used to encrypt the current challenge, and
467 the encrypted form will be sent back the the server for
470 Alternatively, you may have Kerberos available. This may require you
471 to set up some magic files in your home directory on your client
472 machine, but means you can omit specifying any password at all.<P>
474 Fetchmail supports two different Kerberos schemes. One is a
475 POP3 variant called KPOP; consult the documentation of your mail
476 server to see if you have it (one clue is the string "krb-IV" in the
477 greeting line on port 110). The other is an IMAP facility described
478 by RFC1731. You can tell if this one is present by looking for
479 AUTH=KERBEROS_V4 in the CAPABILITY response.<P>
481 If you are fetching mail from a CompuServe POP3 account, you can use
482 their RPA authentication (which works much like APOP). See <a
483 href="#S3">S3</a> for details. If you are fetching mail from
484 Microsoft Exchange, you will be able to use NTLM.<P>
486 Your POP3 server may have the RFC1938 OTP capability to use one-time
487 passwords (if it doesn't, you can get OTP patches for the 2.2 version
488 of the Qualcomm popper from <a href="#cmetz">Craig Metz</a>). To check
489 this, look for the string "otp-" in the greeting line. If you see it,
490 and your fetchmail was built with OPIE support compiled in (see the
491 distribution INSTALL file), fetchmail will detect it also. When using
492 OTP, you will specify a password but it will not be sent en clair.<P>
494 Sadly, there is at present (September 1999) no OTP or APOP-like
495 facility generally available on IMAP servers. However, there do exist
496 patches which will OTP-enable the University of Washington IMAP
497 daemon, version 4.2-FINAL. We have a report that the GSSAPI support
498 in fetchmail works with the GSSAPI support in the most recent version
499 of UW IMAP. Or you can use <a href="#K5">SSL</a> for complete
500 end-to-end encryption if you have an SSL-enabled mailserver.<P>
502 You can get both POP3 and IMAP OTP patches from <a name="cmetz">Craig
504 href="http://www.inner.net/pub/">http://www.inner.net/pub/</a>.<P>
505 These patches use a SASL authentication method named "X-OTP" because
506 there is not currently a standard way to do this; fetchmail also uses
507 this method, so the two will interoperate happily. They better,
508 because this is how Craig gets his mail ;-)<P>
511 <h2><a name="G10">G10. Is any special configuration needed to use a dynamic IP address?</a></h2>
513 Yes. In order to avoid giving indigestion to certain picky MTAs
514 (notably <a href="#T3">exim</a>), fetchmail always makes the RCPT TO
515 address it feeds the MTA a fully qualified one with a hostname part.
516 Normally it does this by appending @ and "localhost", but when you are
517 using Kerberos or ETRN mode it will append @ and your machine's
518 fully-qualified domain name (FQDN).<P>
520 Appending the FQDN can create problems when fetchmail is running in daemon
521 mode and outlasts the dynamic IP address assignment your client
522 machine had when it started up.<P>
524 Since the new IP address (looked up at RCPT TO interpretation time)
525 doesn't match the original, the most benign possible result is that
526 your MTA thinks it's seeing a relaying attempt and refuses. More
527 frequently, fetchmail will try to connect to a nonexistent host
528 address and time out. Worst case, you could up forwarding your mail
529 to the wrong machine!<P>
531 Use the <code>smtpaddress</code> option to force the appended hostname
532 to one with a (fixed) IP address of 127.0.0.1 in your
533 <code>/etc/hosts</code>. (The name `localhost' will usually work; or
534 you can use the IP address itself).<P>
536 Only one fetchmail option interacts directly with your IP address,
537 `<code>interface</code>'. This option can be used to set the gateway
538 device and restrict the IP address range fetchmail will use. Such a
539 restriction is sometimes useful for security reasons, especially on
540 multihomed sites. See <a href="#C3">C3</a>.<P>
542 I recommend against trying to set up the <code>interface</code> option
543 when initially developing your poll configuration -- it's never
544 necessary to do this just to get a link working. Get the link working
545 first, observe the actual address range you see on connections, and
546 add an <code>interface</code> option (if you need one) later.<P>
548 If you're using a dynamic-IP configuration, one other (non-fetchmail)
549 problem you may run into with outgoing mail is that some sites will
550 bounce your email because the hostname your giving them isn't real
551 (and doesn't match what they get doing a reverse DNS on your
552 dynamically-assigned IP address). If this happens, you need to hack
553 your sendmail so it masquerades as your host. Setting<P>
559 in your <code>sendmail.cf</code> will work, or you can set<P>
562 MASQUERADE_AS(smarthost.here)
565 in the m4 configuration and do a reconfigure. (In both cases, replace
566 <code>smarthost.here</code> with the actual name of your mailhost.)
567 See the <a href="http://www.lege.com/sendmail-FAQ.txt">sendmail
568 FAQ</a> for more details.<P>
571 <h2><a name="G11">G11. Is any special configuration needed to use firewalls?</a></h2>
573 No. You can use fetchmail with SOCKS, the standard tool for
574 indirecting TCP/IP through a firewall. You can find out about SOCKS,
575 and download the SOCKS software including server and client code, at
576 the <a href="http://www.socks.nec.com/">SOCKS distribution
579 The specific recipe for using fetchmail with a firewall is at <a
583 <h2><a name="G12">G12. Is any special configuration needed to <em>send</em> mail?</a></h2>
585 A user asks: but how do we send mail out to the POP3 server? Do I need
586 to implement another tool or will fetchmail do this too?<p>
588 Fetchmail only handles the receiving side. The sendmail or other
589 preinstalled MTA on your client machine will handle sending mail
590 automatically; it will ship mail that is submitted while the
591 connection is active, and put mail that is submitted while
592 the connection is inactive into the outgoing queue.<P>
594 Normally, sendmail is also run periodically (every 15 minutes on most
595 Linux systems) in a mode that tries to ship all the mail in the
596 outgoing queue. If you have set up something like pppd to
597 automatically dial out when your kernel is called to open a TCP/IP
598 connection, this will ensure that the mail gets out.<P>
601 <h2><a name="G13">G13. Is fetchmail Y2K-compliant?</a></h2>
603 Fetchmail is fully Y2K-compliant.<P>
605 Fetchmail could theoretically have problems when the 32-bit time_t
606 counters roll over in 2038, but I doubt it. Timestamps aren't used
607 for anything but log entry generation. Anyway, if you aren't running
608 on a 64-bit machine by then, you deserve to lose.<P>
611 <h2><a name="G14">G14. Is there a way in fetchmail to support disconnected IMAP mode?</a></H2>
613 No. Fetchmail is a mail transport agent, best understood as a protocol
614 gateway between POP3/IMAP servers and SMTP. Disconnected operation
615 requires an elaborate interactive client. It's a very different problem.<p>
618 <h2><a name="G15">G15. How will fetchmail perform under heavy loads?</a></h2>
620 Fetchmail streams message bodies line-by-line; the most core it
621 ever requires per message is enough memory to hold the RFC822 header, and
622 that storage is freed when body processing begins. It is, accordingly,
623 quite economical in its use of memory.<p>
625 After startup time, a fetchmail running in daemon mode stats its
626 configuration file once per poll cycle to see whether it has changed
627 and should be rescanned. Other than that, a fetchmail in normal
628 operation doesn't touch the disk at all; that job is left up to the
629 MTA or MDA the fetchmail talks to.<p>
631 Fetchmail's performance is usually bottlenecked by latency on the POP
632 server or (less often) on the TCP/IP link to the server. This is not
633 a problem readily solved by tuning fetchmail, or even by buying more
634 TCP/IP capacity (which tends to improve bandwidth but not necessarily
638 <h2><a name="B1">B1. Lex bombs out while building the fetchmail lexer.</a></h2>
640 In the immortal words of Alan Cox the last time this came up: ``Take
641 the Solaris lex and stick it up the backside of a passing Sun
642 salesman, then install <a
643 href="ftp://prep.ai.mit.edu/ftp/pub/gnu">flex</a> and use that. All
644 will be happier.''<P>
646 I couldn't have put it better myself, and ain't going to try now.<P>
649 <h2><a name="B2">B2. I get link failures when I try to build fetchmail.</a></h2>
651 If you get errors resembling these<P>
654 mxget.o(.text+0x35): undefined referenceto `__res_search'
655 mxget.o(.text+0x99): undefined reference to`__dn_skipname'
656 mxget.o(.text+0x11c): undefined reference to`__dn_expand'
657 mxget.o(.text+0x187): undefined reference to`__dn_expand'
658 make: *** [fetchmail] Error 1
661 then you must add "-lresolv" to the LOADLIBS line in your Makefile
662 once you have installed the `bind' package.<P>
665 <h2><a name="F1">F1. Why does my old .fetchmailrc file no longer work?</a></h2>
667 <h3>If your file predates 5.1.0</h3>
669 In 5.1.0, the <tt>auth</tt> keyword and option were changed to
672 <h3>If your file predates 4.5.5</h3>
674 If the <code>dns</code> option is on (the default), you may need to
675 make sure that any hostname you specify (for mail hosts or for an SMTP
676 target) is a canonical fully-qualified hostname). In order to avoid
677 DNS overhead and complications, fetchmail no longer tries to derive
678 the fetchmail client machine's canonical DNS name at startup.<P>
680 <h3>If your file predates 4.0.6:</h3>
682 Just after the `<CODE>via</CODE>' option was introduced, I realized
683 that the interactions between the `<CODE>via</CODE>',
684 `<CODE>aka</CODE>', and `<CODE>localdomains</CODE>' options were out
685 of control. Their behavior had become complex and confusing, so much so
686 that I was no longer sure I understood it myself. Users were being
687 unpleasantly surprised.<P>
689 Rather than add more options or crock the code, I re-thought it. The
690 redesign simplified the code and made the options more orthogonal, but
691 may have broken some complex multidrop configurations.
693 Any multidrop configurations that depended on the name just after the
694 `<CODE>poll</CODE>' or `<CODE>skip</CODE>' keyword being still
695 interpreted as a DNS name for address-matching purposes, even in the
696 presence of a `<CODE>via</CODE>' option, will break.<P>
698 It is theoretically possible that other unusual configurations (such
699 as those using a non-FQDN poll name to generate Kerberos IV tickets) might
700 also break; the old behavior was sufficiently murky that we can't be
701 sure. If you think this has happened to you, contact the maintainer.<P>
703 <h3>If your file predates 3.9.5:</h3>
705 The `<code>remote</code>' keyword has been changed to `<code>folder</code>'.
706 If you try to use the old keyword, the parser will utter a warning.<P>
708 <h3>If your file predates 3.9:</h3>
710 It could be because you're using a .fetchmailrc that's written in the
711 old popclient syntax without an explicit `<CODE>username</CODE>'
712 keyword leading the first user entry attached to a server entry.
714 This error can be triggered by having a user option such as `<CODE>keep</CODE>'
715 or `<CODE>fetchall</CODE>' before the first explicit username. For
716 example, if you write<p>
719 poll openmail protocol pop3
720 keep user "Hal DeVore" there is hdevore here
723 the `<CODE>keep</CODE>' option will generate an entire user entry with
724 the default username (the name of fetchmail's invoking user).<p>
726 The popclient compatibility syntax was removed in 4.0. It complicated
727 the configuration file grammar and confused users.<p>
729 <h3>If your file predates 2.8:</h3>
731 The `<CODE>interface</CODE>', `<CODE>monitor</CODE>' and
732 `<CODE>batchlimit</CODE>' options changed after 2.8.<p>
734 They used to be global options with `<CODE>set</CODE>' syntax like the
735 batchlimit and logfile options. Now they're per-server options, like
736 `<CODE>protocol</CODE>'.<p>
738 If you had something like<p>
741 set interface = "sl0/10.0.2.15"
744 in your .fetchmailrc file, simply delete that line and insert
745 `interface sl0/10.0.2.15' in the server options part of your `defaults'
748 Do similarly for any `<CODE>monitor</CODE>' or `<CODE>batchlimit</CODE>' options.<p>
751 <h2><a name="F2">F2. The .fetchmailrc parser won't accept my all-numeric user name.</a></h2>
753 Either upgrade to a post-5.0.5 fetchmail or put string quotes around it. :-)<p>
755 The configuration file parser in older fetchmail versions treated any
756 all-numeric token as a number, which confused it when it was
757 expecting a name. String quoting forces the token's class.<p>
759 The lexical analyzer in 5.0.6 and beyond is smarter and assumes
760 any token following "username" or "password" is a string.
763 <h2><a name="F3">F3. The .fetchmailrc parser won't accept my host or username beginning with `no'.</a></h2>
765 See <a href="#F2">F2</a> You're caught in an unfortunate crack between
766 the newer-style syntax for negated options (`no keep', `no rewrite'
767 etc.) and the older style run-on syntax (`nokeep', `norewrite'
770 Upgrade to a 5.0.6 or later fetchmail, or put string quotes around your
774 <h2><a name="F4">F4. I'm getting a `parse error' message I don't understand.</a></h2>
776 The most common cause of mysterious parse errors is putting a server
777 option after a user option. Check the manual page; you'll probably
778 find that by moving one or more options closer to the `poll' keyword
779 you can eliminate the problem.<p>
781 Yes, I know these ordering restrictions are hard to understand.
782 Unfortunately, they're necessary in order to allow the `defaults'
786 <h2><a name="C1">C1. Why do I need a .fetchmailrc when running as root on my own machine?</a></h2>
788 Ian T. Zimmerman <itz@rahul.net> asked:<p>
790 On the machine where I'm the only real user, I run fetchmail as root
791 from a cron job, like this:<p>
794 fetchmail -u "itz" -p POP3 -s bolero.rahul.net
797 This used to work as is (with no .fetchmailrc file in root's home
798 directory) with the last version I had (1.7 or 1.8, I don't
799 remember). But with 2.0, it RECPs all mail to the local root user,
800 unless I create a .fetchmailrc in root's home directory containing:<p>
803 skip bolero.rahul.net proto POP3
807 It won't work if the second line is just "<CODE>user itz</CODE>". This is silly.<p>
809 It seems fetchmail decides to RECP the `default local user' (i.e. the
810 uid running fetchmail) unless there are local aliases, and the
811 `default' aliases (itz->itz) don't count. They should.<p>
815 No they shouldn't. I thought about this for a while, and I don't much
816 like the conclusion I reached, but it's unavoidable. The problem is
817 that fetchmail has no way to know, in general, that a local user `itz'
820 "Ah!" you say, "Why doesn't it check the password file to see if the remote
821 name matches a local one?" Well, there are two reasons.<p>
823 One: it's not always possible. Suppose you have an SMTP host declared
824 that's not the machine fetchmail is running on? You lose.<p>
826 Two: How do you know server itz and SMTP-host itz are the same person?
827 They might not be, and fetchmail shouldn't assume they are unless
828 local-itz can explicitly produce credentials to prove it (that is, the
829 server-itz password in local-itz's .fetchmailrc file.).<p>
831 Once you start running down possible failure modes and thinking about
832 ways to tinker with the mapping rules, you'll quickly find that all the
833 alternatives to the present default are worse or unacceptably
834 more complicated or both.<p>
837 <h2><a name="C2">C2. How can I arrange for a fetchmail daemon to get killed when I log out?</a></h2>
839 The easiest way to dispatch fetchmail on logout (which will work
840 reliably only if you have just one login going at any time) is to
841 arrange for the command `fetchmail -q' to be called on logout. Under
842 bash, you can arrange this by putting `fetchmail -q' in the file
843 `~/.bash_logout'. Most csh variants execute `~/.logout' on logout.
844 For other shells, consult your shell manual page.<p>
846 Automatic startup/shutdown of fetchmail is a little harder to arrange
847 if you may have multiple login sessions going. In the contrib
848 subdirectory of the fetchmail distribution there is some shell code
849 you can add to your .bash_login and .bash_logout profiles that will
850 accomplish this. Thank James Laferriere <babydr@nwrain.net> for
853 Some people start up and shut down fetchmail using the ppp-up and
854 ppp-down scripts of pppd.<p>
857 <h2><a name="C3">C3. How do I know what interface and address to use with --interface?</a></h2>
859 This depends a lot on your local networking configuration (and right
860 now you can't use it at all except under Linux and the newer BSDs). However,
861 here are some important rules of thumb that can help. If they don't
862 work, ask your local sysop or your Internet provider.<p>
864 First, you may not need to use --interface at all. If your machine
865 only ever does SLIP or PPP to one provider, it's almost certainly by a
866 point to point modem connection to your provider's local subnet that's
867 pretty secure against snooping (unless someone can tap your phone or
868 the provider's local subnet!). Under these circumstances, specifying
869 an interface address is fairly pointless.<p>
871 What the option is really for is sites that use more than one
872 provider. Under these circumstances, typically one of your provider
873 IP addresses is your mailserver (reachable fairly securely via the
874 modem and provider's subnet) but the others might ship your packets
875 (including your password) over unknown portions of the general
876 Internet that could be vulnerable to snooping. What you'll use
877 --interface for is to make sure your password only goes over the
880 To determine the device:<p>
883 <li> If you're using a SLIP link, the correct device is probably sl0.
884 <li> If you're using a PPP link, the correct device is probably ppp0.
885 <li> If you're using a direct connection over a local network such as
886 an ethernet, use the command `netstat -r' to look at your routing table.
887 Try to match your mailserver name to a destination entry; if you don't
888 see it in the first column, use the `default' entry. The device name
889 will be in the rightmost column.
892 To determine the address and netmask:<p>
895 <li> If you're talking to slirp, the correct address is probably 10.0.2.15,
896 with no netmask specified. (It's possible to configure slirp to present
897 other addresses, but that's the default.)
899 <li> If you have a static IP address, run `ifconfig <device>', where <device>
900 is whichever one you've determined. Use the IP address given after
901 "inet addr:". That is the IP address for your end of the link, and is
902 what you need. You won't need to specify a netmask.
904 <li> If you have a dynamic IP address, your connection IP will vary randomly
905 over some given range (that is, some number of the least significant bits
906 change from connection to connection). You need to declare an address
907 with the variable bits zero and a complementary netmask that sets
911 To illustrate the rule for dynamic IP addresses, let's suppose you're
912 hooked up via SLIP and your IP provider tells you that the dynamic
913 address pool is 255 addresses ranging from 205.164.136.1 to
914 205.164.136.255. Then<p>
917 interface "sl0/205.164.136.0/255.255.255.0"
920 would work. To range over any value of the last two octets
921 (65536 addresses) you would use<p>
924 interface "sl0/205.164.0.0/255.255.0.0"
928 <h2><a name="C4">C4. How can I set up support for sendmail's anti-spam features?</a></h2>
930 This answer covers versions of sendmail from 8.8.7 (the version
931 installed in Red Hat 5.1) upwards. If you have an older version,
932 upgrade to sendmail 8.9.<P>
934 Stock sendmails can now do anti-spam exclusions based on a database of
935 filter rules. The human-readable form of the database is at
936 <tt>/etc/mail/deny</tt>. The database itself is at
937 <tt>/etc/mail/deny.db</tt>.<P>
939 The table itself uses email addresses, domain names, and network
940 numbers as keys. For example,</P>
942 spammer@aol.com REJECT
943 cyberspammer.com REJECT
946 <P>would refuse mail from spammer@aol.com, any user from
947 cyberspammer.com (or any host within the cyberspammer.com domain), and
948 any host on the 192.168.212.* network. (This feature can be used to
949 do other things as well; see the <a
950 href="http://www.sendmail.org/m4/anti-spam.html">sendmail
951 documentation</a> for details)</P>
953 To actually set up the database, run
956 makemap hash deny <deny
960 To test, send a message to your mailing address from that host and
961 then pop off the message with fetchmail, using the -v argument. You
962 can monitor the SMTP transaction, and when the FROM address is parsed,
963 if sendmail sees that it is an address in spamlist, fetchmail will
964 flush and delete it.<p>
966 Under no circumstances put your <strong>mailhost</strong> or <strong>any host
967 you accept mail from</strong> using fetchmail into your reject file. You
968 <strong>will</strong> lose mail if you do this!!!<p>
971 <h2><a name="C5">C5. How can I poll some of my mailboxes more/less
972 often than others?</a></h2>
974 Use the <cite>interval</cite> keyword on the ones that should be
975 checked less often. For example, if you do a poll every 5 minutes,
976 and want to poll some mailboxes every 5 minutes and some every 30
977 minutes, use something like this:<p>
980 poll mainsite.example.com proto pop3 user ....
981 poll secondary.example.com proto pop3 interval 6 user ...
984 Then secondary.example.com will be polled every 6th time that
985 mainsite.example.com is polled, which with a polling interval of every
986 5 minutes means that secondary.example.com will be polled every 30
990 <h2><a name="C6">Fetchmail works OK started up manually, but not from an init script.</a></h2>
992 Often, startup scripts have a different environment than an interactive
993 login shell. For instance, $HOME might point to "/root" when you are
994 logged in as root, but it might be either unset, or set to "/" when the
995 startup scripts are running. That means fetchmail at startup can't find
998 Pick a location (such as /etc/fetchmailrc) and use fetchmail's -f
999 option to point fetchmail at it. That should solve the problem.<p>
1002 <h2><a name="C7">C7. How can I forward mail to another host?</a></h2>
1004 To forward mail to a host other than the one you are running fetchmail
1005 on, use the <code>smtphost</code> option. See the manual page for
1009 <h2><a name="T1">T1. How can I use fetchmail with sendmail?</a></h2>
1011 For most sendmails, no special configuration is required. Eric Allman
1012 tells me that if <code>FEATURE(always_add_domain)</code> is included
1013 in sendmail's configuration, you can leave the <code>rewrite</code>
1016 If your sendmail complains ``sendmail does not relay'', make sure
1017 your sendmail,cf file says
1023 so that sendmail recognizes `localhost' as a name of its host.<p>
1025 If you're mailing from another machine on your local network, also
1026 ensure that its IP address is listed in ip_allow or name in name_allow
1027 (usually in /etc/mail/)<p>
1029 If you find that your sendmail doesn't like the address
1030 `FETCHMAIL-DAEMON@localhost' (which is used in the bouncemail
1031 that fetchmail generates), you may have to set
1032 <code>FEATURE(accept_unqualified_senders)</code>.<P>
1034 Günther Leber reports that Digital Unix sendmails won't work with
1035 fetchmail. The symptom is an error message "<code>553 Local configuration
1036 error, hostname not recognized as local</code>". The problem is that
1037 fetchmail normally feeds sendmail with the client machine's host
1038 address in the MAIL FROM line. These sendmails think this means
1039 they're seeing the result of a mail loop and suppress the mail. You
1040 may be able to work around this by running in <code>--invisible</code> mode.<P>
1042 If you want to support multidrop mode, and you can get access to your
1043 mailserver's sendmail.cf file, it's a good idea to add this rule:<P>
1046 H?l?Delivered-To: $u
1049 and declare `<CODE>envelope "Delivered-To:"</CODE>'. This will cause the
1050 mailserver's sendmail to reliably write the appropriate envelope
1051 address into each message before fetchmail sees it, and tell fetchmail
1052 which header it is. With this change, multidrop mode should work
1053 reliably even when the Received header omits the envelope address
1054 (which will typically be the case when the message has multiple
1057 Martijn Lievart has a more detailed recipe in the contrib subdirectory
1058 of the fetchmail source distribution.
1061 <h2><a name="T2">T2. How can I use fetchmail with qmail?</a></h2>
1063 Turn on the <CODE>forcecr</CODE> option; qmail's listener mode doesn't like
1064 header or message lines terminated with bare linefeeds.<p>
1066 (This information is thanks to Robert de Bath
1067 <robert@mayday.cix.co.uk>.)<p>
1069 If a mailhost is using the qmail package (see <a
1070 href="http://pobox.com/~djb/qmail.html">http://pobox.com/~djb/qmail.html</a>)
1071 then, providing the local hosts are also using qmail, it is possible
1072 to set up one fetchmail link to be reliably collect the mail for an
1075 One of the basic features of qmail is the `Delivered-To:' message
1076 header. Whenever qmail delivers a message to a local mailbox it puts
1077 the username and hostname of the envelope recipient on this line. The
1078 major reason for this is to prevent mail loops. <p>
1080 To set up qmail to batch mail for a disconnected site the ISP-mailhost
1081 will have normally put that site in its `virtualhosts' control file so
1082 it will add a prefix to all mail addresses for this site. This results
1083 in mail sent to 'username@userhost.userdom.dom.com' having a
1084 'Delivered-To:' line of the form:<p>
1087 Delivered-To: mbox-userstr-username@userhost.userdom.dom.com
1090 A single host maildrop will be slightly simpler:
1093 Delivered-To: mbox-userstr-username@userhost.dom.com
1096 The ISP can make the 'mbox-userstr-' prefix anything they choose
1097 but a string matching the user host name is likely.<p>
1099 To use this line you must:<p>
1102 <li>Ensure the option `envelope Delivered-To:' is in the fetchmail
1105 <li>Ensure you have a localdomains containing 'userdom.dom.com' or
1106 `userhost.dom.com' respectively.
1109 So far this reliably delivers messages to the correct machine of the
1110 local network, to deliver to the correct user the 'mbox-userstr-'
1111 prefix must be stripped off of the user name. This can be done by
1112 setting up an alias within the qmail MTA on each local machine.
1113 Simply create a dot-qmail file called '.qmail-mbox-userstr-default'
1114 in the alias directory (normally /var/qmail/alias) with the contents:<p>
1117 | ../bin/qmail-inject -a -f"$SENDER" "${LOCAL#mbox-userstr-}@$HOST"
1120 Note this <em>does</em> require a modern /bin/sh.<p>
1122 Peter Wilson adds: <P>
1124 ``My ISP uses "alias-unzzippedcom-" as the prefix, which means that I
1125 need to name my file ".qmail-unzzippedcom-default". This is due to
1126 qmail's assumption that a message sent to user-xyz is handled by the
1127 file ~user/.qmail-xyz (or ~user/.qmail-default).''<p>
1129 Luca Olivetti adds:<P>
1131 If you aren't using qmail locally, or you don't want to set up the
1132 alias mechanism described above, you can use the option `<code>qvirtual
1133 "mbox-userstr-"</code>' in your fetchmail config file to strip the prefix
1134 from the local user name.<p>
1137 <h2><a name="T3">T3. How can I use fetchmail with exim?</a></h2><p>
1139 If you have <CODE>rewrite</CODE> on: <P>
1141 There is an RFC1123 requirement that MAIL FROM and RCPT TO addresses
1142 you pass to it have to be canonical (e.g. with a fully qualified
1143 hostname part). Therefore fetchmail tries to pass fully qualified
1144 RCPT TO addresses. But exim does not by default accept `localhost' as
1145 a fully qualified domain. This can be fixed.<P>
1147 In exim.conf, add `localhost' to your local_domains declaration if it's not
1148 already present. For example, the author's site at thyrsus.com would
1149 have a line reading:<P>
1152 local_domains = thyrsus.com:localhost
1155 If you have <CODE>rewrite</CODE> off:<P>
1157 MAIL FROM is a potential problem if the MTAs upstream from your fetchmail
1158 don't necessarily pass canonicalized From and Return-Path addresses,
1159 and fetchmail's <CODE>rewrite</CODE> option is off. The specific case
1160 where this has come up involves bounce messages generated by sendmail
1161 on your mailer host, which have the (un-canonicalized) origin address
1164 The right way to fix this is to enable the <CODE>rewrite</CODE> option and
1165 have fetchmail canonicalize From and Return-Path addresses with the
1166 mailserver hostname before exim sees them. This option is enabled by
1167 default, so it won't be off unless you turned it off.<p>
1169 If you must run with <CODE>rewrite</CODE> off, there is a switch in exim's
1170 configuration files that allows it to accept domainless MAIL FROM
1171 addresses; you will have to flip it by putting the line <p>
1174 sender_unqualified_hosts = localhost
1177 in the main section of the exim configuration file. Note that this
1178 will result in such messages having an incorrect domain name attached
1179 to their return address (your SMTP listener's hostname rather than
1180 that of the remote mail server). <p>
1183 <h2><a name="T4">T4. How can I use fetchmail with smail?</a></h2><p>
1185 Smail 3.2 is very nearly plug-compatible with sendmail, and may work
1186 fine out of the box.<P>
1188 We have one report that when processing multiple messages from a
1189 single fetchmail session, smail sometimes delivers them in an
1190 order other than received-date order. This can be annoying because it
1191 scrambles conversational threads. This is not fetchmail's problem,
1192 it is an smail `feature' and has been reported to the maintainers
1195 Very recent smail versions require an <code>-smtp_hello_verify</code>
1196 option in the smail config file. This overrides smail's check to see
1197 that the HELO address is actually that of the client machine, which
1198 is never going to be the case when fetchmail is in the picture.
1199 According to RFC1123 an SMTP listener <em>must</em> allow this
1200 mismatch, so smail's new behavior (introduced sometime between
1201 3.2.0.90 and 3.2.0.95) is a bug.<P>
1204 <h2><a name="T5">T5. How can I use fetchmail with SCO's MMDF?</a></h2><p>
1206 MMDF itself is difficult to configure, but it turns out that
1207 connecting fetchmail to MMDF's SMTP channel isn't that hard.
1209 href="http://www.aplawrence.com/Unixart/uucptofetch.html">
1210 MMDF recipe</a> that describes replacing a UUCP link with
1211 fetchmail feeding MMDF.<P>
1214 <h2><a name="T6">T6. How can I use fetchmail with Lotus Notes?</a></h2><p>
1216 The Lotus Notes SMTP gateway tries to deduce when it should convert \n
1217 to \r\n, but its rules are not the intuitive and correct-for-RFC822
1218 ones. Use `forcecr'.<P>
1221 <h2><a name="S1">S1. How can I use fetchmail with qpopper?</a></h2>
1223 Qualcomm's qpopper is probably the best-of-breed among POP3 servers, and
1224 is very widely deployed. Nevertheless, it has some problems which
1225 fetchmail exposes. We recommend using <a href="#G7">IMAP</a> instead if at
1226 all possible. If you must talk to qpopper, here are some problems to
1229 <h3>Problems with retrieving large messages from qpopper 2.53</h3>
1231 Tony Tang <a href="mailto:tony@atn.com.hk"><tony@atn.com.hk></a>
1232 reports that there is a bad intercation between fetchmail and qpopper
1233 2.5.3 under Red Hat Linux versions 5.0 to 5.2, kernels 2.0.34 to
1234 2.0.35. When fetching very large messages (over 700K) from 2.5.3,
1235 fetchmail will hang with a socket error.<p>
1237 This is probably not a fetchmail bug, but rather a symptom of some
1238 problem in the networking stack that qpopper's transmission pattern is
1239 tickling, as fetchpop (another Linux POP client) also displays the hang
1240 but Netscape running under Win95 does not. The problem can also be
1242 href="http://www.eudora.com/freeware/qpop.html">upgrading to qpopper
1245 <h3>Bad interaction with fetchmail 4.4.2 to 4.4.7</h3>
1247 Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction
1248 with Eudora qpopper versions 2.3 and later. See <a href="#X5">X5</a>
1249 for details. The solution is to upgrade your fetchmail.<p>
1252 <h2><a name="S2">S2. How can I use fetchmail with Microsoft Exchange?</a></h2>
1254 Fetchmail now supports the proprietary NTLM mode used with M$ Exchange
1255 servers. To enable this, configure fetchmail with the --enable-NTLM
1256 option and recompile it. Note: if you specify a user option value
1257 that looks like `user@domain', the part to the left of the @ will
1258 be passed as the username and the part to the right as the NTLM domain.<P>
1260 M$ Exchange violates the POP3 RFCs. Its LIST command does not reveal
1261 the real sizes of mail in the pop mailbox, but the sizes of the
1262 compressed versions in the exchange mail database (thanks to Arjan De
1263 Vet and Guido Van Rooij for alerting us to this problem).<P>
1265 Fetchmail works with M$ Exchange, despite this brain damage. Two
1266 features are compromised. One is that the --limit option will not
1267 work right (it will check against compressed and not actual sizes).
1268 The other is that a too-small SIZE argument may be passed to your
1269 ESMTP listener, assuming you're using one (this should not be a
1270 problem unless the actual size of the message is above the listener's
1271 configured length limit).<P>
1273 Somewhat belatedly, I've learned that there's supposed to be a
1274 registry bit that can fix this breakage:<P>
1277 HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1278 System\Pop3 Compatibility
1281 This is a bitmask that controls the variations from the standard protocol.
1282 The bits defined are:<P>
1286 <DD>Report exact message sizes for the LIST command
1288 <DD>Allow arbitrary linear whitespace between commands and arguments
1290 <DD>Enable the LAST command
1292 <DD>Allow an empty PASS command (needed for users with blank
1293 passwords, but illegal in the protocol)
1295 <DD>Relax the length restrictions for arguments to commands (protocol
1296 requires 40, but some user names may be longer than that).
1298 <DD>Allow spaces in the argument to the USER command.
1301 There's another one that may be useful to know about:<P>
1304 KEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MsExchangeIs\Parameters
1305 System\Pop3 Performance
1310 <DD>Render messages to a temporary stream instead of sending directly
1311 from the database (should always be on)
1313 Flag unrenderable messages (instead of just failing commands)
1314 (should only be on if you are seeing the problems reported
1317 <DD>Return from the QUIT command before all messages have been deleted.
1320 The Microsoft pod-person who revealed this information to me admitted
1321 that he couldn't find it anywhere in their public knowledge base.<P>
1323 Another specific problem we have seen with Exchange servers has as its
1324 symptom a response to LOGIN that says "NO Ambiguous Alias". Grant
1327 This means that Exchange Server is too f*&#ing stupid to figure
1328 out which mailbox belongs to you. Instead of actually keeping
1329 track of which inbox belongs to which user, it uses some
1330 half-witted, guess-o-matic heuristic to try to guess your
1331 mailbox name from your username.<p>
1333 In your case it doesn't work because your username maps to more
1334 than one mailbox. For some people it doesn't work because
1335 their username maps to zero mailboxes. This is yet another
1336 inept, lame, almost criminally negligent design decision from
1337 our friends in Redmond.<p>
1339 You've got several options:
1343 Try giving fetchmail a username of "/NTDomain/NTUsername/MailboxName".
1345 Get your administrator to configure the server so that
1346 usernames and mailbox names are the same.
1348 Get your administrator to add an alias that maps your
1349 username explicitly to your mailbox name.
1352 But, the best option involves a tactical nuclear weapon (an old
1353 ASROC will do), pissing off a lot people who live downwind from
1354 Redmond, and your choice of any Linux, NetBSD, FreeBSD, or
1357 I'll provide the CD.
1360 <h2><a name="S3">S3. How can I use fetchmail with CompuServe RPA?</a></h2>
1362 First, make sure your fetchmail has the RPA support compiled in.
1363 Stock fetchmail binaries (such as you might get from an RPM) don't.
1364 You can check this by looking at the output of <code>fetchmail -V</code>;
1365 if you see the string "+RPA" after the version ID you're good to go,
1366 otherwise you'll have to build your own from sources (see the INSTALL
1367 file in the source distribution for directions).<P>
1369 Give your CompuServe pass-phrase in lower case as your password. Add
1370 `@compuserve.com' to your user ID so that it looks like `user
1371 <UserID>@compuserve.com', where <UserID> can be either
1372 your numerical userID or your E-mail nickname. An RPA-enabled
1373 fetchmail will automatically check for csi.com in the POP server's
1374 greeting line. If that's found, and your user ID ends with
1375 `@compuserve.com', it will query the server to see if it
1376 is RPA-capable, and if so do an RPA transaction rather than a
1377 plain-text password handshake.<P>
1379 <strong>Warning:</strong> the debug (-v -v) output of fetchmail will show
1380 your pass-phrase in Unicode!<P>
1382 These two .fetchmailrc entries show the difference between an RPA and
1383 non-RPA configuration:
1386 # This version will use RPA
1387 poll csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1388 user "CSERVE_USER@compuserve.com" there with password "CSERVE_PASSWORD"
1389 is LOCAL_USER here options fetchall stripcr
1391 # This version will not use RPA
1392 poll non-rpa.csi.com via "pop.site1.csi.com" with proto POP3 and options no dns
1393 user "CSERVE_USER" there with password "CSERVE_POP3_PASSWORD"
1394 is LOCAL_USER here options fetchall stripcr
1398 <h2><a name="S4">S4. How can I use fetchmail with Demon Internet's SDPS?</a></h2>
1400 <h3>Single-drop mode</h3>
1402 You can get fetchmail to download the email for just one user from
1403 Demon Internet's POP3 server by giving it a username consisting of your
1404 Demon user name followed by your account name, with an at-sign between
1407 For example, to download email for the user <philh@vision25.demon.co.uk>,
1408 you could use the following .fetchmailrc file:<P>
1411 set postmaster "philh"
1412 poll pop3.demon.co.uk with protocol POP3:
1413 user "philh@vision25" is philh
1416 <h3>Multi-drop mode</h3>
1418 Demon Internet's SDPS service is an implementation of POP3. All messages
1419 have a Received: header added when they enter the maildrop, like this:
1422 Received: from punt-1.mail.demon.net by mailstore for fred@xyz.demon.co.uk
1423 id 899963657:10:27896:0; Thu, 09 Jul 98 05:54:17 GMT
1426 To enable multi-drop mode you need to tell fetchmail that 'mailstore' is
1427 the name of the host which accepted the mail, and let it know the
1428 hostname part(s) of your E-mail address. The following example assumes
1429 that your hostname is xyz.demon.co.uk, and that you have also bought
1430 "mail forwarding" for the domain my-company.co.uk (in which case your
1431 MTA must also be configured to accept mail sent to user@my-company.co.uk)
1434 poll pop3.demon.co.uk proto pop3 aka mailstore no dns:
1435 localdomains xyz.demon.co.uk my-company.co.uk
1436 user xyz is * fetchall
1439 The `fetchall' command ensures that all mail is downloaded. If you
1440 want to leave mail on the server use `uidl' and `keep'; Demon does not
1441 implement the obsolete `top' command, because SDPS combines messages
1442 residing on two separate punt clusters into a single POP3 maildrop.
1443 If you do use UIDL, be aware that the "user@host" form for fetching
1444 mail from a particular Demon host will confuse fetchmail's UIDL code;
1447 Note that Demon may delete mail on the server which is more than 30
1448 days old; see their <a
1449 href="http://www.demon.net/info/helpdesk/demon_products/mail/sdps-tech.shtml">
1450 POP3 page</a> for details.<P>
1452 <h3>The SDPS extension</h3>
1454 There's a different way to do multidrop. It's not necessary on Demon
1455 Internet, since fetchmail can parse Received addresses, but the person
1456 who implemented this didn't know that. It may be useful if Demon
1457 Internet ever changes mail transports.<P>
1459 SDPS includes a non-standard extension for retrieving the envelope of a
1460 message (*ENV), which fetchmail optionally supports if compiled with the
1461 --enable-SDPS option. If you have it, the first line of the fetchmail -V
1462 response will include the string "+SDPS".<P>
1464 Once you have SDPS compiled in, fetchmail in POP3 mode will
1465 automatically detect when it's talking to a Demon Internet host in
1466 multidrop mode, and use the *ENV extension to get an envelope To address.<P>
1468 The autodetection works by looking at the hostname in the POP3
1469 greeting line; if you're accessing Demon Internet through a proxy it
1470 may fail. To force SDPS mode, pick "sdps" as your protocol.<P>
1473 <h2><a name="S5">S5. How can I use fetchmail with usa.net's servers?</a></h2>
1475 Enable `<CODE>fetchall</CODE>'. A user reports that the 2.2 version
1476 of USA.NET's POP server reports that you must use the
1477 `<CODE>fetchall</CODE>' option to make sure that all of the mail is
1478 retrieved, otherwise some may be left on the server. This is almost
1479 certainly a server bug.<P>
1481 The usa.net servers (at least in their 2.2 version, June 1998) don't
1482 handle the TOP command properly, either. Regardless of the argument
1483 you give it, they retrieve only about 10 lines of the message.
1484 Fetchmail normally uses TOP for message retrieval in order to avoid
1485 marking messages seen, but `<CODE>fetchall</CODE>' forces it to use
1488 (Note: Other failure modes have been reported on usa.net's servers.
1489 They seem to be chronically flaky. We recommend finding another
1493 <h2><a name="S6">S6. How can I use fetchmail with HP OpenMail?</a></h2>
1495 No special configuration is required, but OpenMail versions prior to
1496 6.0 have an annoying bug similar to the big one in <a
1497 href="#S2">Microsoft Exchange</a>. The message sizes it gives in the
1498 LIST are rounded to the nearest 1024 bytes. It also has a nasty habit
1499 of discarding headers it doesn't recognize, such as X- and Resent-
1502 As with M$ Exchange, the only real fix for these problems is to get a
1503 POP (or preferably IMAP) server that isn't brain-dead. OpenMail's
1504 project manager claims these bugs have been fixed in 6.0.<P>
1507 <h2><a name="S8">S8. How can I use fetchmail with Hotmail?</a></h2>
1509 You can't, yet. But Hugo Rabson has written a script called `hotmole'
1510 that can retrieve Hotmail mail via the web using Lynx. The script
1512 href="http://www.jin-sei-kai.demon.co.uk/hugo/linux.html">
1513 Hugo Rabson's Linux page</a>, but we're told that project is dead and
1514 the web page seems to be gone.<P>
1517 <h2><a name="S9">S9. How can I use fetchmail with MSN?</a></h2>
1519 You can't. MSN uses something that looks like POP3, except the
1520 authentication part is nonstandard. And of course they don't
1521 document it, so nobody but their Windows clients can speak it.<p>
1523 This is a customer lock-in tactic; we recommend boycotting MSN as the
1524 only appropriate response.<p>
1526 As of 5.0.8, we have support for the client side of NTLM
1527 authentication. It's possible this may enable fetchmail to talk to
1528 MSN; if so, somebody should report it so this FAQ can be corrected.<p>
1531 <h2><a name="S10">S10. How can I use fetchmail with SpryNet?</a></h2>
1533 The SpryNet POP3 servers mark a message queried with TOP as seen.
1534 This means that if your connection drops in mid-message, it may end
1535 up invisibly stuck on your mail spool. Use the <code>fetchall</code>
1536 flag to ensure that it's recovered on the next cycle.<p>
1539 <h2><a name="S11">S11. How can I use fetchmail with FTGate?</a></h2>
1541 The FTGate V2 server (and possibly older versions as well) has a weird
1542 bug. It answers OK twice to a TOP request! Use the
1543 <code>fetchall</code> option to force use of RETR and work around this
1547 <h2><a name="S12">S12. How can I use fetchmail with MailMax?</a></h2>
1549 You can't. At least not if you want to be able to see attachments.
1550 MailMax has a bug; it reports the message length with attachments
1551 but doesn't download them on TOP or RETR. <p>
1554 <h2><a name="S13">S13. How can I use fetchmail with Novell GroupWise?</a></h2>
1556 The Novell GroupWise IMAP server would be better named GroupFoolish;
1557 it is (according to the designer of IMAP) unusably broken. Among
1558 other things, it doesn't include a required content length in its
1559 BODY[TEXT] response.<p>
1561 Fetchmail works around this problem, but we strongly recommend voting
1562 with your dollars for a server that isn't brain-dead. If you stick
1563 with code as shoddy as GroupWise seems to be, you will probably pay
1564 for it with other problems.<p>
1567 <h2><a name="S14">S14. How can I use fetchmail with InterChange?</a></h2>
1569 You can't. At least not if you want to be able to see attachments.
1570 InterChange has a bug similar to the MailMax server; it reports the
1571 message length with attachments but doesn't download them on TOP or
1575 <h2><a name="K1">K1. How can I use fetchmail with SOCKS?</a></h2>
1577 Giuseppe Guerini added a --with-socks option that supports linking
1578 with socks library. If you specify the value of this option as
1579 ``yes'', the configure script will try to find the Rconnect library
1580 and set the makefile up to link it. You can also specify a directory
1581 containing the Rconnect library.<p>
1583 Alan Schmitt has added a similar --with-socks5 option that may work
1584 better if you have a recent version of the SOCKS library.
1587 <h2><a name="S7">S7. How can I use fetchmail with geocities POP3 servers?</a></h2>
1589 Nathan Cutler reports that the the mail.geocities.com POP3 servers
1590 fail to include the first Received line of the message in the send to
1591 fetchmail. This can solve problems if your MUA interprets Received
1592 continuations as body lines and doesn't parse any of the following
1595 Workaround is to use "mda" keyword or "-mda" switch:
1597 mda "sed -e '1s/^\t/Received: /' | formail | /usr/bin/procmail -d <user>"
1599 Replace \t with exactly one tabulation character.
1601 You should also consider using "fetchall" option because Geocities' servers
1602 sometimes think that the first 45 messages have already been read.<P>
1604 Fix: Get an email provider that doesn't suck. The pop-up ads on
1605 Geocities are lame, you should boycott them anyway.<P>
1608 <h2><a name="K2">K2. How can I use fetchmail with IPv6 and IPsec?</a></h2>
1610 To use fetchmail with IPv6, you need a system that supports IPv6, the "Basic
1611 Socket Interface Extensions for IPv6" (RFC 2133).
1612 This currently means that you need to have a BSD/OS or NetBSD system with
1613 the NRL IPv6+IPsec software distribution or a Linux system with the latest
1614 experimental kernel and net-tools. It should not be hard to build fetchmail on
1615 other IPv6 implementations if you can port the inet6-apps kit.<P>
1617 To use fetchmail with networking security (read: IPsec), you need a system that
1618 supports IPsec, the API described in the "Network Security API for Sockets"
1619 (draft-metz-net-security-api-01.txt), and the inet6-apps kit. This currently
1620 means that you need to have a BSD/OS or NetBSD system with the NRL IPv6+IPsec
1621 software distribution. A Linux IPsec implementation supporting this API will
1622 probably appear in the coming months.<P>
1624 The NRL IPv6+IPsec software distribution can be obtained from: <a
1625 href="http://web.mit.edu/network/isakmp">http://web.mit.edu/network/isakmp</a>
1628 The inet6-apps kit can be obtained from <a
1629 href="ftp://ftp.ipv6.inner.net/pub/ipv6">ftp://ftp.ipv6.inner.net/pub/ipv6</a>
1630 (via IPv6) or <a href="ftp://ftp.inner.net/pub/ipv6">
1631 ftp://ftp.inner.net/pub/ipv6</a> (via IPv4).<P>
1633 More information on using IPv6 with Linux can be obtained from:
1636 <a href="http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html">
1637 http://www.bieringer.de/linux/IPv6/IPv6-HOWTO/IPv6-HOWTO.html</a>
1639 <a href="http://www.ipv6.inner.net/ipv6">http://www.ipv6.inner.net/ipv6</a>
1642 <a href="http://www.inner.net/ipv6">http://www.inner.net/ipv6</a> (via IPv4)
1646 <h2><a name="K3">K3. How can I get fetchmail to work with ssh?</a></h2>
1648 We have three recipes for this. The first is easy to set up,
1649 but only supports one user at a time.<P>
1651 <h3>Single-User POP3</h3>
1653 First, a lightly edited version of a recipe from Masafumi NAKANE:<p>
1655 1. You must have ssh (the ssh client) on the local host and sshd (ssh
1656 server) on the remote mail server. And you have to configure ssh so
1657 you can login to the sshd server host without a password. (Refer to ssh
1658 man page for several authentication methods.)<p>
1660 2. Add something like following to your .fetchmailrc file: <p>
1663 poll mailhost port 1234 via localhost with proto pop3:
1664 preconnect "ssh -f -L 1234:mailhost:110 mailhost
1665 </dev/null >/dev/null; sleep 5";
1668 The sleep is needed on slower machines to prevent fetchmail from
1669 trying to open the socket before ssh actually makes it ready. Faster
1670 machines may not need it.<p>
1672 (Note that 1234 can be an arbitrary port number. Privileged ports can
1673 be specified only by root.) The effect of this ssh command is to
1674 forward connections made to localhost port 1234 (in above example) to
1677 This configuration will enable secure mail transfer. All the
1678 conversation between fetchmail and remote pop server will be
1681 If sshd is not running on the remote mail server, you can specify
1682 intermediate host running it. If you do this, however, communication
1683 between the machine running sshd and the POP server will not be encrypted.
1684 And the preconnect line would be like this:<p>
1687 preconnect "ssh -f -L 1234:mailhost:110 sshdhost sleep 20 </dev/null >/dev/null"
1690 You can work this trick with IMAP too, but the port number 110 in the
1691 above would need to become 143. In either case you'll have to specify
1692 a password but the password will not be sent in clear.<p>
1694 There is an explanation of a similar recipe at <a
1695 href="http://sunsite.unc.edu/LDP/HOWTO/mini/Secure-POP+SSH.html">Secure
1696 POP via SSH mini-HOWTO</a>.<P>
1698 <h3>Multi-User POP3</h3>
1700 Second, a recipe from Charlie Brady <cbrady@ind.tansu.com.au>:<p>
1702 Charlie says: "The recipe [from Masafume NAKANE] certainly works, but
1703 the solution I post here is better in a few respects":
1706 <LI>this method will not fail if two or more users attempt to use fetchmail
1708 <LI>you are able to use the full facilities of tcpd to control access
1709 <LI>this method does not depend on the preconnect feature of fetchmail, so
1710 can be used for tunneling of other services as well.
1717 Make sure that the "socket" program is installed on the server
1718 machine. Presently it lives at <a
1719 href="ftp://sunsite.unc.edu/pub/linux/system/network/misc/socket-1.1.tar.gz">
1720 ftp://sunsite.unc.edu/pub/linux/system/network/misc/socket-1.1.tar.gz</a>,
1721 but watch out for a change in version number.<P>
1723 Set up an unprivileged account on your system with a .ssh directory
1724 containing an SSH identity file "identity" with no pass phrase,
1725 "identity.pub" and "known_hosts" containing the host key of your
1726 mailhost. Let's call this account "noddy".
1728 On mailhost, set up no-password access for noddy@yourhost. Add to your
1729 SSH authorized_keys file:
1732 command="socket localhost 110",no-port-forwarding 1024 ......
1735 where "<code>1024 ......</code>" is the content of noddy's identity.pub file.
1737 Create a script /usr/local/bin/ssh.fm and make it executable:
1741 exec ssh -q -C -l your.login.id -e none mailhost socket localhost 110
1744 Add an entry in inetd.conf for whatever port you choose to use - say:
1747 1234 stream tcp nowait noddy /usr/sbin/tcpd /usr/local/bin/ssh.fm
1750 Send a HUP signal to your inetd.
1753 Now just use localhost:1234 to access your POP server.<P>
1755 <h3>Multi-User IMAP</h3>
1757 This is the preferred method. It comes to us from Joerg Dorchain.
1758 The basic idea is to set up a bidirectional encrypted socket connection:<p>
1761 fetchmail <--> ssh <---> sshd <--> imapd
1762 \---local side--/ \-remote side-/
1765 Use ssh-keygen(1) to set up a special ssh identity with no password
1766 and RSA-only authentication, which executes /usr/sbin/imapd when
1767 authenticated. For security reasons all other commands should be
1768 disabled. (There is some security exposure in using an identity
1769 without a passphrase; it means anyone who can get access to your
1770 account could use it to read your mail).<p>
1772 Running ssh-keygen will generate two files. Have it create the
1773 private key to ~/.ssh/identity-imap. Once you have generated the
1774 corresponding public key, prepend this to the line of key data in it:
1777 command="/usr/sbin/imapd",no-port-forwarding,no-agent-forwarding
1780 This identity data has to be appended to ~/.ssh/authorized_keys on the
1781 remote machine, as usual for RSA authentication. Whenever your ssh
1782 uses this identity, the remote side will run imapd. The imapd will
1783 see that it is not running as root and go into preauthenticated
1786 On the client side, use the <code>plugin</code> keyword to make
1787 fetchmail talk to the stdin of the remote ssh. Here's an examople:
1790 poll mail.dorchain.net
1791 with options proto imap, preauth ssh, plugin fetchmail-imap-wrapper
1794 The wrapper script should look like this:<p>
1798 exec ssh -i $HOME/.ssh/identity-imap $1 /usr/sbin/imapd
1802 <h2><a name="K4">K4. What do I have to do to use the IMAP-GSS protocol?</a></h2>
1804 Fetchmail can use RFC1731 GSSAPI authorization to safely identify you
1805 to your IMAP server, as long as you can share Kerberos V credentials
1806 with your mail host and you have a GSSAPI-capable IMAP server.
1807 UW-IMAP (available via FTP at <a
1808 href="ftp://ftp.cac.washington.edu/mail/">ftp.cac.washington.edu</a>)
1809 is the only one I'm aware of and the one I recommend anyway for other
1810 reasons. You'll need version 4.1-FINAL or greater though, and it has
1811 to have GSS support compiled in.<p>
1813 Neither UW-IMAP nor fetchmail compile in support for GSS by default,
1814 since it requires libraries from the Kerberos V distribution
1815 (available via FTP at <a
1816 href="ftp://athena-dist.mit.edu/pub/ATHENA/kerberos">athena-dist.mit.edu</a).
1817 If you have these, compiling in GSS support is simple: add a
1818 <pre>--with-gssapi=[/path/to/krb5/root]</pre> option to configure. For
1819 instance, I have all of my Kerberos V libraries installed under
1820 /usr/krb5 so I run <pre>configure --with-gssapi=/usr/krb5</pre><p>
1822 Setting up Kerberos V authentication is beyond the scope of this FAQ
1823 (you may find Jim Rome's paper <a
1824 href="http://www.ornl.gov/~jar/HowToKerb.html"> How to Kerberize your
1825 site</a> helpful), but you'll at least need to add a credential for
1826 imap/[mailhost] to the keytab of the mail server (IMAP doesn't just
1827 use the host key). Then you'll need to have your credentials ready on
1828 your machine (cf. kinit).<p>
1830 After that things are very simple. Set your protocol to imap-gss in your
1831 .fetchmailrc, and omit the password, since imap-gss doesn't need one. You
1832 can specify a username if you want, but this is only useful if your mailbox
1833 belongs to a username different from your Kerberos principal. <p>
1835 Now you don't have to worry about your password appearing in cleartext in
1836 your .fetchmailrc, or across the network.<p>
1839 <h2><a name="K5">K5. How can I use fetchmail with SSL?</a></h2>
1841 You'll need to have the <a href="http://www.openssl.org/">OpenSSL</a>
1842 libraries installed. Configure with --with-ssl. If you have the
1843 OpenSSL libraries installed in the default location (/usr/local/ssl)
1844 this will suffice. If you have them installed in a non-default
1845 location, you'll need to specify it as an argument to --with-ssl after
1848 Fetchmail binaries built this way support <code>ssl</code>,
1849 <code>sslkey</code>, and <code>sslcert</code> options that control
1850 SSL encryption. You will need to have an SSL-enabled mailserver
1851 to use these options. See the manual page for detals.<p>
1854 <h2><a name="R1">R1. Fetchmail isn't working, and -v shows `SMTP connect failed' messages.</a></h2>
1856 Fetchmail itself is probably working, but your SMTP port 25 listener
1857 is down or inaccessible.<p>
1859 The first thing to check is if you can telnet to port 25 on your smtp
1860 host (which is normally `localhost' unless you've specified an smtp
1861 option in your .fetchmailrc or on the command line) and get a greeting
1862 line from the listener. If the SMTP host is inaccessible or the listener
1863 is down, fix that first.<p>
1865 If the listener seems to be up when you test with telnet, the most
1866 benign and typical problem is that the listener had a momentary seizure
1867 due to resource exhaustion while fetchmail was polling it -- process
1868 table full or some other problem that stopped the listener process
1869 from forking. If your SMTP host is not `localhost' or something else
1870 in /etc/hosts, the fetchmail glitch could also have been caused by
1871 transient nameserver failure. <p>
1873 Try running fetchmail -v again; if it succeeds, you had one of these
1874 kinds of transient glitch. You can ignore these hiccups, because a
1875 future fetchmail run will get the mail through. <p>
1877 If the listener tests up, but you have chronic failures trying to
1878 connect to it anyway, your problem is more serious. One way to work
1879 around chronic SMTP connect problems is to use --mda. But this only
1880 attacks the symptom; you may have a DNS or TCP routing problem. You
1881 should really try to figure out what's going on underneath before it
1882 bites you some other way. <p>
1884 We have one report (from toby@eskimo.com) that you can sometimes solve
1885 such problems by doing an <CODE>smtp</CODE> declaration with an IP
1886 address that your routing table maps to something other than the
1887 loopback device (he used ppp0).<p>
1889 We also have a report that this error can be caused by having an
1890 /etc/hosts file that associates your client host name with more than
1893 It's also possible that your DNS configuration isn't
1894 looking at <code>/etc/hosts</code> at all. If you're using libc5,
1895 look at <code>/etc/resolv.conf</code>; it should say something like
1901 so your <code>/etc/hosts</code> file is checked first. If you're
1902 running GNU libc6, check your <code>/etc/nsswitch.conf</code> file. Make
1903 sure it says something like
1909 again, in order to make sure <code>/etc/hosts</code> is seen first.<P>
1911 If you have a hostname set for your machine, and this hostname does
1912 not appear in /etc/hosts, you will be able to telnet to port 25 and
1913 even send a mail with rcpt to: user@host-not-in-/etc/hosts, but
1914 fetchmail can't seem to get in touch with sendmail, no matter what you
1915 set smtpaddress to.<p>
1917 We had another report from a Linux user of fetchmail 2.1 who solved his SMTP
1918 connection problem by removing the reference to -lresolv from his link
1919 line and relinking. Apparently in some older Linux distributions the
1920 libc bind library version works better.<p>
1922 As of 2.2, the configure script has been hacked so the bind library is
1923 linked only if it is actually needed. So under Linux it won't be, and
1924 this particular cause should go away.<p>
1927 <h2><a name="R2">R2. When I try to configure an MDA, fetchmail doesn't work.</a></h2>
1929 (I hear this one from people who have run into the blank-line problem in <a href="#X1">X1</a>.)<p>
1931 Try sending yourself test mail and retrieving it using the
1932 command-line options `<CODE>-k -m cat</CODE>'. This will dump exactly what
1933 fetchmail retrieves to standard output (plus the Received line
1934 fetchmail itself adds to the headers). <p>
1936 If the dump doesn't match what shows up in your mailbox when you
1937 configure an MDA, your MDA is mangling the message. If it doesn't
1938 match what you sent, then fetchmail or something on the server is
1942 <h2><a name="R3">R3. Fetchmail dumps core when given an invalid rc file.</a></h2>
1944 This is usually reported from AIX or Ultrix, but has even been known
1945 to happen on Linuxes without a recent version of <code>flex</code>
1946 installed. The problem appears to be a result of building with an
1947 archaic version of lex.<P>
1949 Workaround: fix the syntax of your .fetchmailrc file.<P>
1951 Fix: build and install the latest version of <a
1952 href="ftp://prep.ai.mit.edu/~ftp/pub/gnu">flex</a> from the Free
1953 Software Foundation. An FSF <a
1954 href="http://www.gnu.ai.mit.edu/order/ftp.html">mirror site</a>
1955 will help you get it faster.<P>
1958 <h2><a name="R4">R4. Fetchmail dumps core in -V mode, but operates normally otherwise.</a></h2>
1960 We've had this reported to us under Linux using libc-5.4.17 and gcc-2.7.2.
1961 It does not occur with libc-5.3.12 or earlier versions.<p>
1963 Workaround: link with GNU malloc rather than the stock C library malloc.<p>
1965 We're told there is some problem with the malloc() code in that
1966 version which makes it fragile in the presence of multiple free()
1967 calls on the same pointer (the malloc arena gets corrupted).
1968 Unfortunately it appears from doing gdb traces that whatever free()
1969 calls producing the problem are being made by the C library itself, not the
1970 fetchmail code (they're all from within fclose, and not an fclose called
1971 directly by fetchmail, either).<p>
1974 <h2><a name="R5">R5. Running fetchmail in daemon mode doesn't work.</a><br></h2>
1976 We have one report from a SunOS 4.1.4 user that trying to run
1977 fetchmail in detached daemon mode doesn't work, but that using the
1978 same options with -N (nodetach) is OK.<P>
1980 If this happens, you have a specific portability problem with the code
1981 in daemon.c that detaches and backgrounds the daemon fetchmail. Tell
1982 me about it so I can try to fix it. As a workaround, you can start
1983 fetchmail with -N and an ampersand to background it. A Sun user
1988 (fetchmail --nodetach <other params> &)
1991 The extra pair of parens is significant --- it makes sure that the process
1992 detaches from the initial shell (one more shell is started and dies
1993 immediately, detaching fetchmail and making it child of PID 1). This is
1994 important when you start fetchmail interactively and than quit
1995 interactive shell. The line above makes sure fetchmail lives after
1998 This should not happen under Linux or any truly POSIX-conformant Unix.<P>
2001 <h2><a name="R6">R6. Fetchmail hangs when used with pppd.</a></h2>
2003 Your problem may be with pppd's `demand' option. We have a report that
2004 fetchmail doesn't play well with it, but works with pppd if `demand'
2005 is turned off. We have no idea why this is.<p>
2008 <h2><a name="R7">R7. Fetchmail randomly dies with socket errors.</a></h2>
2010 Check the MTU value in your PPP interface reported by
2011 <code>/sbin/ifconfig</code>. If it's over 600, change it in your PPP
2012 options file. (<code>/etc/ppp/options</code> on my box). Here are
2013 option values that work:<P>
2021 <a name="R8">R8. Fetchmail running as root stopped working after an OS upgrade</a></h2>
2023 In RH 6.0, the HOME value in the boot-time root environment changed
2024 from /root to / as the result of a change in init. Move your
2025 .fetchmailrc or use a -f option to explicitly point at the file.
2026 (Oddly, a similar problem has been reported from Debian systems.)<P>
2029 <h2><a name="R9">R9. Fetchmail is timing out after fetching certain
2030 messages but before deleting them</a></h2>
2032 There's a TCP/IP stalling problem under Redhat 6.0 (and possibly other
2033 recent Linuxes) that can cause this symptom. Brian Boutel writes:<p>
2036 TCP timestamps are turned on on my Linux boxes (I assume it's now the
2037 default). This uses 12 extra bytes per segment.
2038 When the tcp connection starts, the other end agrees a MSS of 1460,
2039 and then fragments 1460 byte chunks into 1448 and 12, because
2040 is is not allowing for the timestamp.<p>
2042 Then, for reasons I can't explain, it waits a long time (typically 2
2043 minutes) after the ack is sent before sending the next (fragmented)
2044 packet. Turning off tcp timestamps avoids the fragmentation and
2045 restores normal behaviour. To do this, [execute]<p>
2047 echo 0 > /proc/sys/net/ipv4/tcp_timestamps<p>
2049 I'm still unclear about the details of why this is happening. At least
2050 [now] I am now getting good performance and no queue blocking.
2054 <h2><a name="R10">R10. Fetchmail is timing out during message fetches</a></h2>
2056 This is probably a general networking issue. Sending a "RETR" command will
2057 cause the server to start sending large amounts of data, which means
2058 large packets. If your networking layer has a packet-fragmentation
2059 problem, that's where you'll see it.<p>
2062 <h2><a name="D1">D1. I think I've set up fetchmail correctly, but I'm not getting any mail.</a></h2>
2064 Maybe you have a .forward or alias set up that you've forgotten about. You
2065 should probably remove it.<p>
2067 Or maybe you're trying to run fetchmail in multidrop mode as root
2068 without a .fetchmailrc file. This doesn't do what you think it
2069 should; see question <a href="#C1">C1</a>.<p>
2071 Or you may not be connecting to the SMTP listener. Run fetchmail -v
2072 and see <a href="#R1">R1</a>.<p>
2075 <h2><a name="D2">D2. All my mail seems to disappear after a dropped connection.</a></h2>
2077 One POP3 daemon used in the Berkeley Unix world that reports itself as
2078 POP3 version 1.004 actually throws the queue away. 1.005 fixed that.
2079 If you're running this one, upgrade immediately. (It also truncates
2080 long lines at column 1024)<P>
2082 Many POP servers, if an interruption occurs, will restore the whole
2083 mail queue after about 10 minutes. Others will restore it right
2084 away. If you have an interruption and don't see it right away, cross
2085 your fingers and wait ten minutes before retrying.<P>
2087 Some servers (such as Microsoft's NTMail) are mis-designed to restore
2088 the entire queue, including messages you have deleted. If you have
2089 one of these and it flakes out on you a lot, try setting a small
2090 <code>--fetchlimit</code> value. This will result in more IP connects
2091 to the server, but will mean it actually executes changes to the queue
2094 Qualcomm's qpopper, used at many BSD Unix sites, is better behaved.
2095 If its connection is dropped, it will first execute all DELE commands as
2096 though you had issued a QUIT (this is a technical violation of
2097 the POP3 RFCs, but a good idea in a world of flaky phone lines). Then it
2098 will re-queue any message that was being downloaded at hangup time.
2099 Still, qpopper may require a noticeable amount of time to do deletions
2100 and clean up its queue. (Fetchmail waits a bit before retrying in
2101 order to avoid a `lock busy' error.)<P>
2104 <h2><a name="D3">D3. Mail that was being fetched when I interrupted my fetchmail seems to have been vanished.</a></h2>
2106 Fetchmail only sends a delete mail request to the server when either
2107 (a) it gets a positive delivery acknowledgment from the SMTP
2108 listener, or (b) it gets an error 571 (the spam-filter error) from the
2109 listener. No interrupt can cause it to lose mail.<p>
2111 However, IMAP2bis has a design problem in that its normal fetch
2112 command marks a message `seen' as soon as the fetch command to get it
2113 is sent down. If for some reason the message isn't actually delivered
2114 (you take a line hit during the download, or your port 25 listener
2115 can't find enough free disk space, or you interrupt the delivery in
2116 mid-message) that `seen' message can lurk invisibly in your server
2119 Workaround: add the `<CODE>fetchall</CODE>' keyword to your fetch options.<p>
2121 Solution: switch to an <a href="http://www.imap.org">IMAP4</a> server.<p>
2124 <h2><a name="M1">M1. I've declared local names, but all my multidrop
2125 mail is going to root anyway.</a></h2>
2127 Somehow your fetchmail is never recognizing the hostname part of
2128 recipient names it parses out of To/Cc/envelope-header lines as
2129 matching the name of the mailserver machine. To check this, run
2130 fetchmail in foreground with -v -v on. You will probably see a lot of
2131 messages with the format ``line rejected, %s is not an alias of the
2132 mailserver'' or ``no address matches; forwarding to %s.'' <p>
2134 These errors usually indicate some kind of DNS configuration problem
2135 either on the server or your client machine. <p>
2137 The easiest workaround is to add a `<CODE>via</CODE>' option (if
2138 necessary) and add enough aka declarations to cover all of your
2139 mailserver's aliases, then say `<CODE>no dns</CODE>'. This will take
2140 DNS out of the picture (though it means mail may be uncollected if
2141 it's sent to an alias of the mailserver that you don't have
2144 It would be better to fix your DNS, however. DNS problems can hurt
2145 you in lots of ways, for example by making your machines
2146 intermittently or permanently unreachable to the rest of the net.<P>
2148 Occasionally these errors indicate the sort of header-parsing problem
2149 described in <a href="#M7">M7</a>.<P>
2152 <h2><a name="M2">M2. I can't seem to get fetchmail to route to a local domain properly.</a></h2>
2154 A lot of people want to use fetchmail as a poor man's internetwork
2155 mail gateway, picking up mail accumulated for a whole domain in a single
2156 server mailbox and then routing based on what's in the To/Cc/Bcc lines.<p>
2158 In general, this is not really a good idea. It would be smarter to
2159 just let the mail sit in the mailserver's queue and use fetchmail's
2160 ETRN mode to trigger SMTP sends periodically (of course, this means
2161 you have to poll more frequently than the mailserver's expiration period).
2162 If you can't arrange this, try setting up a UUCP feed.<P>
2164 If neither of these alternatives is available, multidrop mode may do
2165 (though you <em>are</em> going to get hurt by some mailing list
2166 software; see the caveats under THE USE AND ABUSE OF MULTIDROP
2167 MAILBOXES on the man page). If you want to try it, the way to do it
2168 is with the `<CODE>localdomains</CODE>' option.<p>
2170 In general, if you use localdomains you need to make sure of two other
2173 <strong>1. You've actually set up your .fetchmailrc entry to invoke multidrop mode.</strong><p>
2175 Many people set a `<CODE>localdomains</CODE>' list and then forget
2176 that fetchmail wants to see more than one name (or the wildcard `*')
2177 in a `<CODE>here</CODE>' list before it will do multidrop routing.<p>
2179 <strong>2. You may have to set `no envelope'.</strong><p>
2181 Normally, multidrop mode tries to deduce an envelope address from a message
2182 before parsing the To/Cc/Bcc lines (this enables it to avoid losing to mailing
2183 list software that doesn't put a recipient address in the To lines).<p>
2185 Some ways of accumulating a whole domain's messages in a single server
2186 mailbox mean it all ends up with a single envelope address that is
2187 useless for rerouting purposes. You may have to set `<CODE>no
2188 envelope</CODE>' to prevent fetchmail from being bamboozled by this.<p>
2190 Check also answer <a href="#T1">T1</a> on a reliable way to do multidrop
2191 delivery if your ISP (or your mail redirection provider) is using qmail.<p>
2194 <h2><a name="M3">M3. I tried to run a mailing list using multidrop, and I have a mail loop!</a></h2>
2196 This isn't fetchmail's fault. Check your mailing list. If the list
2197 expansion includes yourself or anybody else at your mailserver (that is, not on
2198 the client side) you've created a mail loop. Just chop the host part off any
2199 local addresses in the list.<p>
2201 If you use sendmail, you can check the list expansion with
2202 <CODE>sendmail -bv</CODE>.<p>
2205 <h2><a name="M4">M4. My multidrop fetchmail seems to be having DNS problems.</a></h2>
2207 We have one report from a Linux user (not the same one as in <a
2208 href="#R1">R1</a>!) who solved this problem by removing the reference
2209 to -lresolv from his link line and relinking. Apparently in some
2210 older Linux distributions the libc5 bind library version works
2213 As of 2.2, the configure script has been hacked so the bind library is linked
2214 only if it is actually needed. So under Linux it won't be, and this problem
2218 <h2><a name="M5">M5. I'm seeing long DNS delays before each message is processed.</a></h2>
2220 Use the `<CODE>aka</CODE>' option to pre-declare as many of your
2221 mailserver's DNS names as you can. When an address's host part
2222 matches an aka name, no DNS lookup needs to be done to check it.<p>
2224 If you're sure you've pre-declared all of your mailserver's DNS names,
2225 you can use the `<CODE>no dns</CODE>' option to prevent other hostname
2226 parts from being looked up at all.<p>
2228 Sometimes delays are unavoidable. Some SMTP listeners try to call DNS
2229 on the From-address hostname as a way of checking that the address is valid.<p>
2232 <h2><a name="M6">M6. How do I get multidrop mode to work with majordomo?</a></h2>
2234 In order for sendmail to execute the command strings in the majordomo
2235 alias file, it is necessary for sendmail to think that the mail it
2236 receives via SMTP really is destined for a local user name. A normal
2237 virtual-domain setup results in delivery to the default mailbox,
2238 rather than expansion through majordomo.<P>
2240 Michael <michael@bizsystems.com> gave us a recipe for dealing
2241 with this case that pairs a run control file like this:<P>
2244 poll your.pop3.server proto pop3:
2246 localdomains virtual.localdomain1.com virtual.localdomain2.com ...
2247 user yourISPusername is root * here,
2248 password yourISPpassword fetchall
2251 with a hack on your local sendmail.cf like this:<P>
2254 #############################################
2255 # virtual info, local hack for ruleset 98 #
2256 #############################################
2258 # domains to treat as direct mapped local domain
2260 CVvirtual.localdomain1.com virtual.localdomain2.com ...
2261 ---------------------------
2263 -------------------------
2264 # handle virtual users
2266 R$+ <@ $=V . > $: $1 < @ $j . >
2267 R< @ > $+ < @ $=V . > $: $1 < @ $j . >
2268 R< @ > $+ $: $1
2269 R< error : $- $+ > $* $#error $@ $1 $: $2
2270 R< $+ > $+ < @ $+ > $: $>97 $1
2273 This ruleset just strips virtual domain names off the addresses of incoming
2274 mail. Your sendmail must be 8.8 or newer for this to work. Michael
2278 I use this scheme with 2 virtual domains and the default ISP
2279 user+domain and service about 30 mail accounts + majordomo on my
2280 inside pop3 server with fetchmail and sendmail 8.83
2284 <h2><a name="M7">M7. Multidrop mode isn't parsing envelope addresses from
2285 my Received headers as it should.</a></h2>
2287 It may happen that you're getting what appear to be well-formed
2288 sendmail Received headers, but fetchmail can't seem to extract an
2289 envelope address from them. There can be a couple of reasons for
2292 <h3>Spurious Received lines need to be skipped:</h3>
2294 First, fetchmail might be looking at the wrong Received header.
2295 Normally it looks only on the first one it sees, on the theory that
2296 that one was last added and is going to be the one containing your
2297 mailserver's theory of who the message was addressed to.<P>
2299 Some (unusual) mailserver configurations will generate extra Received
2300 lines which you need to skip. To arrange this, use the optional
2301 skip prefix argument of the `envelope' option; you may need to say
2302 something like `<code>envelope 1 Received</code>' or `<code>envelope 2
2305 <h3>The `by' clause doesn't contain a mailserver alias:</h3>
2307 When fetchmail parses a Received line that looks like
2310 Received: from send103.yahoomail.com (send103.yahoomail.com [205.180.60.92])
2311 by iserv.ttns.net (8.8.5/8.8.5) with SMTP id RAA10088
2312 for <ksturgeon@fbceg.org>; Wed, 9 Sep 1998 17:01:59 -0700
2315 it checks to see if `iserv.ttns.net' is a DNS alias of your mailserver
2316 before accepting `ksturgeon@fbceg.org' as an envelope address. This
2317 check might fail if your DNS were misconfigured, or if you were using `no dns'
2318 and had failed to declare iserv.ttns.net as an alias of your server.<P>
2321 <h2><a name="M8">M8. Users are getting multiple copies of messages.</a></h2>
2323 It's a consequence of multidrop. What's happening is that you have
2324 N users subscribed to the same list. The list software sends N
2325 copies, not knowing they will end up in the same multidrop box. Since
2326 they are both locally addressed to all N users, fetchmail delivers N
2327 copies to each user.<P>
2329 Fetchmail tries to eliminate adjacent duplicate messages in a
2330 multidrop mailbox. However, this logic depends on the message-ID
2331 being identical in both copies. It also depends on the two copies
2332 being adjacent in the server mailbox. The former is usually the case,
2333 but the latter condition sometimes fails in a timing-dependent way if
2334 the server was processing multiple incoming mail streams.
2336 I could eliminate this problem by keeping a list of all message-IDs
2337 received during a poll so far and dropping any message that matches a
2338 seen mail ID. The touble is that this is an O(N**2) operation that
2339 might significantly slow down the retriweval of large mail batches.<P>
2342 <h2><a name="X1">X1. Spurious blank lines are appearing in the headers of fetched mail.</a></h2>
2344 What's probably happening is that the POP/IMAP daemon on your
2345 mailserver is inserting a non-RFC822 header (like X-POP3-Rcpt:) and
2346 something in your delivery path (most likely an old version of the
2347 <em>deliver</em> program, which sendmail often calls to do local delivery) is
2348 failing to recognize it as a header.<p>
2350 This is not fetchmail's problem. The first thing to try is installing
2351 a current version of <em>deliver</em>. If this doesn't work, try to
2352 figure out which other program in your mail path is inserting the
2353 blank line and replace that. If you can't do either of these things,
2354 pick a different MDA (such as procmail) and declare it with the
2355 `<CODE>mda</CODE>' option.<p>
2358 <h2><a name="X2">X2. My mail client can't see a Subject line.</a></h2>
2360 First, see <a href="#X1">X1</a>. This is quite probably the same
2361 problem (X-POP3-Rcpt header or something similar being inserted by
2362 the server and choked on by an old version of <em>deliver</em>).<p>
2364 The O'Reilly sendmail book does warn that IDA sendmail doesn't process
2365 X- headers correctly. If this is your problem, all I can suggest is
2366 replacing IDA sendmail, because it's broken and not RFC822 conformant.<p>
2369 <h2><a name="X3">X3. Messages containing "From" at start of line are being split.</a></h2>
2371 If you know the messages aren't split in your server mailbox, then this
2372 is a problem with your POP/IMAP server, your client-side SMTP listener or
2373 your local delivery agent. Fetchmail cannot split messages.<p>
2375 Some POP server daemons ignore Content-Length headers and split messages on
2376 From lines. We have one report that the 2.1 version of the BSD popper
2377 program (as distributed on Solaris 2.5 and elsewhere) is broken this way.<p>
2379 You can test this. Declare an mda of `cat' and send yourself one
2380 piece of mail containing "From" at start of a line. If you see a
2381 split message, your POP/IMAP server is at fault. Upgrade to a more
2384 Sendmail and other SMTP listeners don't split RFC822 messages either.
2385 What's probably happening is either sendmail's local delivery agent or
2386 your mail reader are not quite RFC822-conformant and are breaking
2387 messages on what it thinks are Unix-style From headers. You can
2388 figure out which by looking at your client-side mailbox with vi or
2389 more. If the message is already split in your mailbox, your local
2390 delivery agent is the problem. If it's not, your mailreader is the
2393 If you can't replace the offending program, take a look at your
2394 sendmail.cf file. There will likely be a line something like<p>
2397 Mlocal, P=/usr/bin/procmail, F=lsDFMShP, S=10, R=20/40, A=procmail -Y -d $u
2400 describing your local delivery agent. Try inserting the `E' option in the
2401 flags part (the F= string). This will make sendmail turn each dangerous
2402 start-of-line From into a >From, preventing programs further downstream
2406 <h2><a name="generic_mangling"><a name="X4">X4. My mail is being mangled in a new and different way</a></a></h2>
2408 The first thing you need to do is pin down what program is doing the
2409 mangling. We don't like getting bug reports about fetchmail that are
2410 actually due to some other program's malfeasance, so please go through
2411 this diagnostic sequence before sending us a complaint.<P>
2413 There are five possible culprits to consider, listed here in the order
2414 they pass your mail:<P>
2417 <li> Programs upstream of your server mailbox.
2418 <li> The POP or IMAP server on your mailserver host.
2419 <li> The fetchmail program itself.
2420 <li> Your local sendmail.
2421 <li> Your LDA (local delivery agent), as called by sendmail or
2422 specified by <code>mda</CODE>.
2425 Often it happens that fetchmail itself is OK, but using it exposes
2426 pre-existing bugs in your downstream software, or your downstream
2427 software has a bad interaction with POP/IMAP. You need to pin down
2428 exactly where the message is being garbled in order to deduce what is
2429 actually going on.<P>
2431 The first thing to do is send yourself a test message, and retrieve it
2432 with a .fetchmailrc entry containing the following (or by running with
2433 the equivalent command-line options):<P>
2436 mda "cat >MBOX" keep fetchall
2439 This will capture what fetchmail gets from the server, except for (a)
2440 the extra Received header line fetchmail prepends, (b) header address
2441 changes due to <code>rewrite</code>, and (c) any end-of-line changes
2442 due to the <code>forcecr</code> and <code>stripcr</code> options.
2443 MBOX will in fact contain what programs downstream of fetchmail
2446 The most common causes of mangling are bugs and misconfigurations in
2447 those downstream programs. If MBOX looks unmangled, you will know
2448 that is what is going on and that it is not fetchmail's problem. Take
2449 a look at the other FAQ items in this section for possible clues about
2450 how to fix your problem.<P>
2452 If MBOX looks mangled, the next thing to do is compare it with your
2453 actual server mailbox (if possible). That's why you specified
2454 <code>keep</code>, so the server copy would not be deleted. If your
2455 server mailbox looks mangled, programs upstream of your server mailbox
2456 are at fault. Unfortunately there is probably little you can do about
2457 this aside from complaining to your site postmaster, and nothing at
2458 all fetchmail can do about it!<P>
2460 More likely you'll find that the server copy looks OK. In that case
2461 either the POP/IMAP server or fetchmail is doing the mangling. To
2462 determine which, you'll need to telnet to the server port and simulate
2463 a fetchmail session yourself. This is not actually hard (both POP3
2464 and IMAP are simple, text-only, line-oriented protocols) but requires
2465 some attention to detail. You should be able to use a fetchmail -v
2466 log as a model for a session, but remember that the "*" in your LOGIN
2467 or PASS command dump has to be replaced with your actual password.<P>
2469 The objective of manually simulating fetchmail is so you can see
2470 exactly what fetchmail sees. If you see a mangled message, then your
2471 server is at fault, and you probably need to complain to your
2472 mailserver administrators. However, we like to know what the broken
2473 servers are so we can warn people away from them. So please send
2474 us a transcript of the session including the mangling <em>and the
2475 server's initial greeting line</em>. Please tell us anything else
2476 you think might be useful about the server, like the server host's
2477 operating system.<P>
2479 If your manual fetchmail simulation shows an unmangled message,
2480 congratulations. You've found an actual fetchmail bug, which is a
2481 pretty rare thing these days. Complain to us and we'll fix it.
2482 Please include the session transcript of your manual fetchmail
2483 simulation along with the other things described in the FAQ entry on
2484 <a href="#G3">reporting bugs</a>.
2487 <h2><a name="X5">X5. Using POP3, retrievals seems to be fetching too much!</a></h2>
2489 This may happen in versions of fetchmail after 4.4.1 and before 4.4.8.
2490 Versions after 4.4.1 use POP3's TOP command rather than RETR, in order
2491 to avoid marking the message seen (leaving it unseen is helpful for
2492 later recovery if you lose your connection in the middle of a
2495 Versions of fetchmail from 4.4.2 through 4.4.7 had a bad interaction
2496 with Eudora qpopper versions 2.3 and later. The TOP bounds check was
2497 fooled by an overflow condition in the TOP argument. Decrementing the
2498 TOP argument in 4.4.7 fixed this.<P>
2500 Fix: Upgrade to a later version of fetchmail.<P>
2502 Workaround: set the <code>fetchall</code> option. Under POP3
2503 this has the side effect of forcing RETR use.<P>
2506 <h2><a name="X6">X6. My mail attachments are being dropped or mangled.</a></h2>
2508 This isn't fetchmail's doing -- fetchmail never drops lines in message
2509 bodies or attachments. It may be your POP server, or it may be the
2510 sender's mail user agent (or a bad combination of both).<p>
2512 The Mail Max POP3 server and the InterChange and Imail IMAP servers
2513 are known to simply drop MIME attachments when uploading messages.
2514 We've had sporadic reports of problems with Microsoft Exchange and
2515 Outlook servers. Windows- and NT-based POP servers seem especially
2516 prone to mangle attachments. If you are running one of these,
2517 replacing your server with a Unix machine is probably the only
2518 effective solution.<p>
2520 We've also had a report that Lotus Notes sometimes trashes the
2521 MIME type of messages. In particular, it seems to modify MIME
2522 headers introducing type application/pdf, mangling the type
2523 to application/octet-stream. It may corrupt other MIME types
2526 The IMAP service of Lotus Domino has a known bug in the way it
2527 generates MIME Content-type headers (observed on Lotus Domino 5.0.2b).
2528 It's a subtle one that doesn't show up when Netscape Messenger and
2529 other clients use a FETCH BODY[] to grab the whole message. When
2530 fetchmail uses FETCH RFC822.HEADER and FETCH RFC822.TEXT to get first
2531 the header and then the body, Domino generates different Boundary tags
2532 for each part, .e.g. one tag is declared in the Content-type header and
2533 another is used to separate the MIME parts in the body. This doesn't
2536 Another rich source of attachment problems is Microsoft Exchange and
2537 Microsoft Outlook. If you see unreadable attachments with a
2538 ContentType of "application/x-tnef", you're having this problem. The
2539 <a href="http://world.std.com/~damned/software.html">TNEF</a> utility
2542 Rob Funk explains: Unfortunately there also remain many mail user
2543 agents that don't write correct MIME messages. One big offender is Sun
2544 MailTool attachments, which are formatted enough like MIME that some
2545 programs could get confused; these are generated by the mailtool and
2546 dtmail programs (the mail programs in Sun's OpenWindows and CDE
2549 One solution to problems related to misformatted MIME attachments is
2550 the <a href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/">emil</a>
2552 href="ftp://ftp.uu.se/pub/unix/networking/mail/emil/TUTORIAL.html">tutorial</a>
2553 file at that site for details on emil. It is useful for
2554 converting character sets, attachment encodings, and attachment
2555 formats. At this writing, emil does not appear to have been
2556 maintained since a patch to version 2.1.0beta9 in late 1997, but it is
2559 One good way of using emil is from within procmail. You can have
2560 procmail look for signs of problematic message formatting, and pipe
2561 those messages through emil to be fixed. emil will not always be able
2562 to fix the problem, in which case the message is unchanged.<p>
2564 A possible rule to be inserted into a .procmailrc file for using emil
2569 * 1^1 ^Content-Type: \/X-sun[^;]*
2570 * 1^1 ^Content-Type: \/application/mac-binhex[^;]*
2571 * 1^1 ^Content-Transfer-Encoding: \/x-binhex[^;]*
2572 * 1^1 ^Content-Transfer-Encoding: \/x-uuencode[^;]*
2574 LOG="Converting $MATCH
2577 | emil -A B -T Q -B BA -C iso-8859-1 -H Q -F MIME \
2578 | gawk '{gsub(/\r\n?/,"\n");print $0}'
2582 The "1^1" in the conditions is a way of specifying to procmail that if
2583 any one of the four listed expressions is found in the message, the
2584 total condition is considered true, and the message gets passed into
2585 emil. These four subconditions check whether the message has a Sun
2586 attachment, a binhex attachment, or a uuencoded attachment; there are
2587 others that could be added to check these things better and to check
2588 other relevant conditions. The "LOG=" line writes a line into the
2589 procmail log; the lone double-quote beginning the following line makes
2590 sure the log entry gets an end-of-line character. The call to gawk
2591 (GNU awk) is for fixing end-of-line conventions, since emil sometimes
2592 leaves those in the format of the originating machine; it could
2593 probably be replaced with a sed subsitution.<p>
2595 The emil call itself tries to ensure that the message uses:
2597 <li> BinHex encoding for any Apple Macintosh-only attachments
2598 <li> Quoted-Printable encoding for text (when necessary)
2599 <li> Base64 Encoding for binary attachments
2600 <li> iso-8859-1 character set for text (unfortunately emil can't yet
2601 convert from windows-1252 to iso-8859-1)
2602 <li> Quoted-Printable encoding for headers
2603 <li> MIME attachment format
2606 Most of these (the primary exceptions being the character set and the
2607 Apple binary format) are as they should be for good internet
2608 interoperability.<p>
2610 Some mail servers (Lotus Domino is a suspect here) mangle
2611 Sun-formatted messages, so the conversion to MIME needs to happen
2612 before such programs see the message. The ideal is to rid the world
2613 of Sun-formatted messages: don't use mailtool for sending attachments
2614 (it doesn't understand MIME anyway, and most of the world doesn't
2615 understand its attachments, so it really shouldn't be used at all),
2616 and make sure dtmail is set to use MIME rather than mailtool's format.<p>
2619 <h2><a name="O1">O1. The --logfile option doesn't work if the logfile doesn't exist.</a></h2>
2621 This is a feature, not a bug. It's in line with normal practice for
2622 system daemons and allows you to suppress logging by removing the log,
2623 without hacking potentially fragile startup scripts. To get around
2624 it, just touch(1) the logfile before you run fetchmail (this will have
2625 no effect on the contents of the logfile if it already exists).<P>
2628 <h2><a name="O2">O2. Every time I get a POP or IMAP message the header
2629 is dumped to all my terminal sessions.</a></h2>
2631 Fetchmail uses the local sendmail to perform final delivery, which
2632 Netscape and other clients doesn't do; the announcement of new messages
2633 is done by a daemon that sendmail pokes. There should be a ``biff''
2634 command to control this. Type
2640 to turn it off. If this doesn't work, try the command
2646 which is essentially what <code>biff -n</code> will do. If this
2647 doesn't work, comment out any reference to ``comsat'' in your
2648 /etc/inetd.conf file and restart inetd.<P>
2650 In Slackware Linux distributions, the last line in /etc/profile is
2662 to solve the problem system-wide.<P>
2665 <h2><a name="O3">O3. Does fetchmail reread its rc file every poll cycle?</a></h2>
2667 No, but versions 5.2.2 and later will notice when you modify your rc
2668 file and restart, reading it.
2671 <h2><a name="O4">O4. Why do deleted messages show up again when I take
2672 a line hit while downloading?</a></h2>
2674 Because you're using a POP3 other than Qualcomm qpopper, or an IMAP
2675 with a long expunge interval.<P>
2677 According to the POP3 RFCs, deletes aren't actually performed until
2678 you issue the end-of-session QUIT command. Fetchmail cannot fix this,
2679 because doing it right takes cooperation from the server. There are
2680 two possible remedies:<P>
2682 One is to switch to qpopper (the free POP3 server from Qualcomm,
2683 the Eudora people). The qpopper software violates the POP3 RFCs by
2684 doing an expunge (removing deleted messages) on a line hangup, as well
2685 as on processing a QUIT command.<P>
2687 The other (which we recommend) is to switch to <a
2688 href="http://www.imap.org">IMAP</a>. IMAP has an explicit expunge
2689 command and fetchmail normally uses it to delete messages immediately
2690 after they are downloaded.<P>
2692 If you get very unlucky, you might take a line hit in the window
2693 between the delete and the expunge. If you've set a longer expunge
2694 interval, the window gets wider. This problem should correct itself
2695 the next time you complete a successful query.<P>
2698 <h2><a name="O5">O5. Why is fetched mail being logged with my name, not the real From address?</a></h2>
2700 Because logging is done based on the address indicated by the sending
2701 SMTP's MAIL FROM, and some listeners are picky about that address.<p>
2703 Some SMTP listeners get upset if you try to hand them a MAIL FROM
2704 address naming a different host than the originating site for your
2705 connection. This is a feature, not a bug -- it's supposed to help
2706 prevent people from forging mail with a bogus origin site. (RFC 1123
2707 says you shouldn't do this exclusion...)<p>
2709 Since the originating site of a fetchmail delivery connection is
2710 localhost, this effectively means these picky listeners will barf on
2711 any MAIL FROM address fetchmail hands them with an @ in it!<p>
2713 Versions 2.1 and up try the header From address first and fall back to
2714 the calling-user ID. So if your SMTP listener isn't picky, the log
2718 <h2><a name="O6">O6. I'm seeing long sendmail delays or hangs near the start of each poll cycle.</a></h2>
2720 Sendmail does a hostname lookup when it first starts up, and also each
2721 time it gets a HELO in listener mode.<p>
2723 Your resolver configuration may be causing one of these lookups to
2724 fail and time out. Check <code>/etc/resolv.conf</code> and
2725 <code>/etc/hosts</code> file. Make sure your hostname and
2726 fully-qualified domain name are both in <code>/etc/hosts</code>, and
2727 that hosts is looked at before DNS is queried. You probably also want
2728 your remote mail server(s) to be in the hosts file.<p>
2730 You can suppress the startup-time lookup if need to by reconfiguring
2731 with <code>FEATURE(nodns)</code>.<p>
2733 Configuring your bind library to cache DNS lookups locally may help,
2734 and is a good idea for speeding up other services as well. Switching to
2735 a faster MTA like qmail or exim might help. <p>
2738 <h2><a name="O7">O7. Why doesn't fetchmail deliver mail in date-sorted order?</a></h2>
2740 Because that's not the order the server hands it to fetchmail in.<P>
2742 Fetchmail getting mail from a POP server delivers mail in the order
2743 that your server delivers mail. Fetchmail can't do anything about
2744 this; it's a limitation of the underlying POP protocol.<P>
2746 In theory it might be possible for fetchmail in IMAP mode to sort
2747 messages by date, but this would be in violation of two basics of
2748 fetchmail's design philosophy: (a) to be as simple and transparent a
2749 pipe as possible, and (b) to <em>hide</em>, rather than emphasize, the
2750 differences between the remote-fetch protocols it uses.<P>
2752 Re-ordering messages is a user-agent function, anyway.<P>
2755 <h2><a name="O8">O8. I'm using pppd. Why isn't my monitor option working?</a></h2>
2757 There is a combination of circumstances that can confuse fetchmail.
2758 If you have set up demand dialing with pppd, and pppd has an idle
2759 timeout, and you have lcp-echo-interval set, then the
2760 lcp-echo-interval time must be longer than the pppd idle timeout.
2761 Otherwise it is going keep increasing the packet counters that fetchmail
2762 relies upon, triggering fetchmail into polling after its own delay
2763 interval and thus preventing the pppd link from ever reaching its
2764 inactivity timeout.<p>
2767 <h2><a name="O9">O9. Why does fetchmail keep retrieving the same messages
2770 First, check to see that you haven't enabled the <cite>keep</cite>
2771 and <cite>fetchall</cite> option. If you have, turn <cite>keep</cite> off.<p>
2773 This can also happen when some other mail client is logged in to your
2774 mail server, if it uses a simple exclusive-locking scheme (and many,
2775 especially most POP3 servers, do exactly that). Your fetchmail is
2776 able to retrieve the messages, but because the mailbox is write-locked
2777 by the other instance yours can neither mark messages seen or delete them.
2778 The solution is to either (a) wait for the other client to finish, or (b)
2782 <table width="100%" cellpadding=0><tr>
2783 <td width="30%">Back to <a href="index.html">Fetchmail Home Page</a>
2784 <td width="30%" align=center>To <a href="/~esr/sitemap.html">Site Map</a>
2785 <td width="30%" align=right>$Date: 2000/03/30 00:40:56 $
2788 <P><ADDRESS>Eric S. Raymond <A HREF="mailto:esr@thyrsus.com"><esr@snark.thyrsus.com></A></ADDRESS>
2793 compile-command: "(cd ~/WWW; upload fetchmail/fetchmail-FAQ.html)"