2 .\" ** The above line should force tbl to be used as a preprocessor **
4 .\" Manual page in man(7) format with tbl(1) macros for fetchmail
6 .\" For license terms, see the file COPYING in this directory.
8 .TH fetchmail 1 "fetchmail 6.3.2" "fetchmail" "fetchmail reference manual"
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2 (legacy, to be removed from future
30 release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.
31 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
32 these protocols are listed at the end of this manual page.)
36 is primarily intended to be used over on-demand TCP/IP links (such as
37 SLIP or PPP connections), it may also be useful as a message transfer
38 agent for sites which refuse for security reasons to permit
39 (sender-initiated) SMTP transactions with sendmail.
43 is used with a POP or an IMAP server, it has two fundamental modes of
44 operation for each user account from which it retrieves mail:
45 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
47 assumes that all messages in the user's account are intended for a single
48 recipient. An individual mail message will not be inspected for recipient
49 information, rather, the identity of the recipient will either default to
50 the local user currently executing \fIfetchmail\fR,
51 or else will need to be explicitly specified in the configuration file.
52 Singledrop-mode is used when the fetchmailrc configuration contains at
53 most a single local user specification for a given server account.
57 is not able to assume that there is only a single recipient, but rather
58 that the mail server account actually contains mail intended for any
59 number of different recipients. Therefore,
61 must attempt to deduce the proper "envelope recipient" from the mail
62 headers of each message. In this mode of operation
64 almost resembles an MTA, however it is important to note that neither
65 the POP nor IMAP protocols were intended for use in this fashion, and
66 hence envelope information is not directly available. Instead,
68 must resort to a process of informed guess-work in an attempt to
69 discover the true envelope recipient of a message. Even if this
70 information is present in the headers, the process can
71 be error-prone and is dependent upon the specific mail server used
72 for mail retrieval. Multidrop-mode is used when more than one local
73 user is specified for a particular server account in the configuration
74 file. Note that the forgoing discussion of singledrop- and
75 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
76 methods, since they are based upon the SMTP protocol which
77 specifically provides the envelope recipient to \fIfetchmail\fR.
79 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
80 port 25 on the machine it is running on (localhost), just as though it
81 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
82 the SMTP server with an envelope recipient derived in the manner described
83 previously. The mail will then be
84 delivered locally via your system's MDA (Mail Delivery Agent, usually
85 \fIsendmail\fR(8) but your system may use a different one such
86 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
87 delivery-control mechanisms (such as \fI.forward\fR files) normally
88 available through your system MDA and local delivery agents will
89 therefore work automatically.
91 If no port 25 listener is available, but your fetchmail configuration
92 was told about a reliable local MDA, it will use that MDA for local
97 is available, it will assist you in setting up and editing a
98 fetchmailrc configuration. It runs under the X window system and
99 requires that the language Python and the Tk toolkit be present on your
100 system. If you are first setting up fetchmail for single-user mode, it
101 is recommended that you use Novice mode. Expert mode provides complete
102 control of fetchmail configuration, including the multidrop features.
103 In either case, the 'Autoprobe' button will tell you the most capable
104 protocol a given mailserver supports, and warn you of potential problems
107 .SH GENERAL OPERATION
110 is controlled by command-line options and a run control file,
111 .IR ~/.fetchmailrc\fR ,
112 the syntax of which we describe in a later section (this file is what
113 the \fIfetchmailconf\fR program edits). Command-line options override
117 Each server name that you specify following the options on the
118 command line will be queried. If you don't specify any servers
119 on the command line, each 'poll' entry in your
121 file will be queried.
123 To facilitate the use of
125 in scripts and pipelines, it returns an appropriate exit code upon
126 termination -- see EXIT CODES below.
128 The following options modify the behavior of \fIfetchmail\fR. It is
129 seldom necessary to specify any of these once you have a
130 working \fI.fetchmailrc\fR file set up.
132 Almost all options have a corresponding keyword which can be used to
137 Some special options are not covered here, but are documented instead
138 in sections on AUTHENTICATION and DAEMON MODE which follow.
142 Displays the version information for your copy of
144 No mail fetch is performed.
145 Instead, for each server specified, all the option information
146 that would be computed if
148 were connecting to that server is displayed. Any non-printables in
149 passwords or other string names are shown as backslashed C-like
150 escape sequences. This option is useful for verifying that your
151 options are set the way you want them.
154 Return a status code to indicate whether there is mail waiting,
155 without actually fetching or deleting mail (see EXIT CODES below).
156 This option turns off daemon mode (in which it would be useless). It
157 doesn't play well with queries to multiple sites, and doesn't work
158 with ETRN or ODMR. It will return a false positive if you leave read but
159 undeleted mail in your server mailbox and your fetch protocol can't
160 tell kept messages from new ones. This means it will work with IMAP,
161 not work with POP2, and may occasionally flake out under POP3.
164 Silent mode. Suppresses all progress/status messages that are
165 normally echoed to standard output during a fetch (but does not
166 suppress actual error messages). The \-\-verbose option overrides this.
169 Verbose mode. All control messages passed between
171 and the mailserver are echoed to stdout. Overrides \-\-silent.
172 Doubling this option (\-v \-v) causes extra diagnostic information
178 Retrieve both old (seen) and new messages from the mailserver. The
179 default is to fetch only messages the server has not marked seen.
180 Under POP3, this option also forces the use of RETR rather than TOP.
181 Note that POP2 retrieval behaves as though \-\-all is always on (see
182 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
187 Keep retrieved messages on the remote mailserver. Normally, messages
188 are deleted from the folder on the mailserver after they have been retrieved.
191 option causes retrieved messages to remain in your folder on the
192 mailserver. This option does not work with ETRN or ODMR.
196 Delete retrieved messages from the remote mailserver. This
197 option forces retrieved mail to be deleted. It may be useful if
198 you have specified a default of \fBkeep\fR in your
199 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
202 POP3/IMAP only. This is a dangerous option and can cause mail loss when
203 used improperly. It deletes old (seen) messages from the mailserver
204 before retrieving new messages. Warning: This can cause mail loss if
205 you check your mail with other clients than fetchmail, and cause
206 fetchmail to delete a message it had never fetched before. Similarly, if
207 your local MTA hangs and fetchmail is aborted, the next time you run
208 fetchmail, it will delete mail that was never delivered to you. You
209 should probably not use this option in your configuration file. What you
210 probably want is the default setting: if you don't specify '\-k', then
211 fetchmail will automatically delete messages after successful
212 delivery. This option does not work with ETRN and ODMR.
215 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
216 mailserver before retrieving new messages. The size limit should be
217 separately specified with the \-\-limit option. This option does not
218 work with ETRN or ODMR.
219 .SS Protocol and Query Options
221 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
222 (Keyword: proto[col])
223 Specify the protocol to use when communicating with the remote
224 mailserver. If no protocol is specified, the default is AUTO.
226 may be one of the following:
229 Tries IMAP, POP3, and POP2 (skipping any of these for which support
230 has not been compiled in).
232 Post Office Protocol 2 (legacy, to be removed from future release)
234 Post Office Protocol 3
236 Use POP3 with old-fashioned MD5-challenge authentication.
238 Use POP3 with RPOP authentication.
240 Use POP3 with Kerberos V4 authentication on port 1109.
242 Use POP3 with Demon Internet's SDPS extensions.
244 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR automatically detects their capabilities).
246 Use the ESMTP ETRN option.
248 Use the the On-Demand Mail Relay ESMTP profile.
251 All these alternatives work in basically the same way (communicating
252 with standard server daemons to fetch mail already delivered to a
253 mailbox on the server) except ETRN and ODMR. The ETRN mode
254 allows you to ask a compliant ESMTP server (such as BSD sendmail at
255 release 8.8.0 or higher) to immediately open a sender-SMTP connection
256 to your client machine and begin forwarding any items addressed to
257 your client machine in the server's queue of undelivered mail. The
258 ODMR mode requires an ODMR-capable server and works similarly to
259 ETRN, except that it does not require the client machine to have
264 Force UIDL use (effective only with POP3). Force client-side tracking
265 of 'newness' of messages (UIDL stands for "unique ID listing" and is
266 described in RFC1939). Use with 'keep' to use a mailbox as a baby
267 news drop for a group of users. The fact that seen messages are skipped
268 is logged, unless error logging is done through syslog while running in
269 daemon mode. Note that fetchmail may automatically enable this option
270 depending on upstream server capabilities. Note also that this option
271 may be removed and forced enabled in a future fetchmail version. See
275 .B \-P <portnumber> | \-\-service <servicename>
276 (Keyword: service) Since version 6.3.0.
277 The service option permits you to specify a service name to connect to.
278 You can specify a decimal port number here, if your services database
279 lacks the required service-port assignments. See the FAQ item R12 and
280 the \-\-ssl documentation for details. This replaces the older \-\-port
283 .B \-\-port <portnumber>
285 Obsolete version of \-\-service that does not take service names.
287 this option may be removed from a future version.
289 .B \-\-principal <principal>
291 The principal option permits you to specify a service principal for
292 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
295 .B \-t <seconds> | \-\-timeout <seconds>
297 The timeout option allows you to set a server-nonresponse
298 timeout in seconds. If a mailserver does not send a greeting message
299 or respond to commands for the given number of seconds,
300 \fIfetchmail\fR will hang up on it. Without such a timeout
301 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
302 down host. This would be particularly annoying for a \fIfetchmail\fR
303 running in background. There is a default timeout which fetchmail\~\-V
304 will report. If a given connection receives too many timeouts in
305 succession, fetchmail will consider it wedged and stop retrying,
306 the calling user will be notified by email if this happens.
308 .B \-\-plugin <command>
309 (Keyword: plugin) The plugin option allows you to use an external
310 program to establish the TCP connection. This is useful if you want
311 to use socks, SSL, ssh, or need some special firewalling setup. The
312 program will be looked up in $PATH and can optionally be passed the
313 hostname and port as arguments using "%h" and "%p" respectively (note
314 that the interpolation logic is rather primitive, and these token must
315 be bounded by whitespace or beginning of string or end of string).
316 Fetchmail will write to the plugin's stdin and read from the plugin's
319 .B \-\-plugout <command>
321 Identical to the plugin option above, but this one is used for the SMTP
322 connections (which will probably not need it, so it has been separated
325 .B \-r <name> | \-\-folder <name>
327 Causes a specified non-default mail folder on the mailserver (or
328 comma-separated list of folders) to be retrieved. The syntax of the
329 folder name is server-dependent. This option is not available under
333 (Keyword: tracepolls)
334 Tell fetchmail to poll trace information in the form 'polling %s
335 account %s' to the Received line it generates, where the %s parts are
336 replaced by the user's remote name and the poll label (the Received
337 header also normally includes the server's true name). This can be
338 used to facilitate mail filtering based on the account it is being
343 Causes the connection to the mail server to be encrypted via SSL. Connect
344 to the server using the specified base protocol over a connection secured
345 by SSL. SSL support must be present at the server.
347 Note that fetchmail may still try to negotiate TLS even if this option
348 is not given. You can use the \-\-sslproto option to defeat this
349 behavior or tell fetchmail to negotiate a particular SSL protocol.
351 If no port is specified, the connection is attempted to the well known
352 port of the SSL version of the base protocol. This is generally a
353 different port than the port used by the base protocol. For IMAP, this
354 is port 143 for the clear protocol and port 993 for the SSL secured
355 protocol, for POP3, it is port 110 for the clear text and port 995 for
356 the encrypted variant.
358 If your system lacks the corresponding entries from /etc/services, see
359 the \-\-service option and specify the numeric port number as given in
360 the previous paragraph (unless your ISP had directed you to different
361 ports, which is uncommon however).
363 .B \-\-sslcert <name>
365 Specifies the file name of the client side public SSL certificate. Some
366 SSL encrypted servers may require client side keys and certificates for
367 authentication. In most cases, this is optional. This specifies
368 the location of the public key certificate to be presented to the server
369 at the time the SSL session is established. It is not required (but may
370 be provided) if the server does not require it. Some servers may
371 require it, some servers may request it but not require it, and some
372 servers may not request it at all. It may be the same file
373 as the private key (combined key and certificate file) but this is not
378 Specifies the file name of the client side private SSL key. Some SSL
379 encrypted servers may require client side keys and certificates for
380 authentication. In most cases, this is optional. This specifies
381 the location of the private key used to sign transactions with the server
382 at the time the SSL session is established. It is not required (but may
383 be provided) if the server does not require it. Some servers may
384 require it, some servers may request it but not require it, and some
385 servers may not request it at all. It may be the same file
386 as the public key (combined key and certificate file) but this is not
387 recommended. If a password is required to unlock the key, it will be
388 prompted for at the time just prior to establishing the session to the
389 server. This can cause some complications in daemon mode.
391 .B \-\-sslproto <name>
393 Forces an SSL protocol. Possible values are '\fBssl2\fR',
394 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
395 handshake does not work for your server. To defeat automatic TLSv1
396 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
397 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
402 Causes fetchmail to strictly check the server certificate against a set of
403 local trusted certificates (see the \fBsslcertpath\fR option). If the server
404 certificate is not signed by one of the trusted ones (directly or indirectly),
405 the SSL connection will fail. This checking should prevent man-in-the-middle
406 attacks against the SSL connection. Note that CRLs are seemingly not currently
407 supported by OpenSSL in certificate verification! Your system clock should
408 be reasonably accurate when using this option!
410 .B \-\-sslcertpath <directory>
411 (Keyword: sslcertpath)
412 Sets the directory fetchmail uses to look up local certificates. The default
413 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
414 it - every time you add or modify a certificate in the directory, you need
415 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
418 .B \-\-sslfingerprint <fingerprint>
419 (Keyword: sslfingerprint)
420 Specify the fingerprint of the server key (an MD5 hash of the key) in
421 hexadecimal notation with colons separating groups of two digits. The letter
422 hex digits must be in upper case. This is the default format OpenSSL uses,
423 and the one fetchmail uses to report the fingerprint when an SSL connection
424 is established. When this is specified, fetchmail will compare the server key
425 fingerprint with the given one, and the connection will fail if they do not
426 match. This can be used to prevent man-in-the-middle attacks.
428 To obtain the fingerprint of a certificate stored in the file cert.pem,
432 openssl x509 \-in cert.pem \-noout \-md5 \-fingerprint
437 .SS Delivery Control Options
439 .B \-S <hosts> | \-\-smtphost <hosts>
440 (Keyword: smtp[host])
441 Specify a hunt list of hosts to forward mail to (one or more
442 hostnames, comma-separated). Hosts are tried in list order; the first
443 one that is up becomes the forwarding target for the current run. If
444 this option is not specified, 'localhost' is used as the default.
445 Each hostname may have a port number following the host name. The
446 port number is separated from the host name by a slash; the default
447 port is "smtp". If you specify an absolute path name (beginning with
448 a /), it will be interpreted as the name of a UNIX socket accepting
449 LMTP connections (such as is supported by the Cyrus IMAP daemon)
453 \-\-smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
456 This option can be used with ODMR, and will make fetchmail a relay
457 between the ODMR server and SMTP or LMTP receiver.
459 .B \-\-fetchdomains <hosts>
460 (Keyword: fetchdomains)
461 In ETRN or ODMR mode, this option specifies the list of domains the
462 server should ship mail for once the connection is turned around. The
463 default is the FQDN of the machine running
466 .B \-D <domain> | \-\-smtpaddress <domain>
467 (Keyword: smtpaddress) Specify the domain to be appended to addresses
468 in RCPT TO lines shipped to SMTP. When this is not specified, the name
469 of the SMTP server (as specified by \-\-smtphost) is used for SMTP/LMTP
470 and 'localhost' is used for UNIX socket/BSMTP.
472 .B \-\-smtpname <user@domain>
474 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
475 The default user is the current local user.
477 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
479 Specifies the list of numeric SMTP errors that are to be interpreted
480 as a spam-block response from the listener. A value of \-1 disables
481 this option. For the command-line option, the list values should
484 .B \-m <command> | \-\-mda <command>
485 (Keyword: mda) You can force mail to be passed to an MDA directly
486 (rather than forwarded to port 25) with the \-\-mda or \-m option. To
487 avoid losing mail, use this option only with MDAs like maildrop or
488 MTAs like sendmail that return a nonzero status on disk-full and other
489 resource-exhaustion errors; the nonzero status tells fetchmail that
490 delivery failed and prevents the message from being deleted off the
491 server. If \fIfetchmail\fR is running as root, it sets its user id to
492 that of the target user while delivering mail through an MDA. Some
493 possible MDAs are "/usr/sbin/sendmail \-i \-f %F \-\- %T" (\fBNote:\fR
494 with several original sendmail versions, you must omit the \-\-),
495 "/usr/bin/deliver" and "/usr/bin/maildrop \-d %T". Local delivery
496 addresses will be inserted into the MDA command wherever you place a
497 %T; the mail message's From address will be inserted where you place
498 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
499 both %T and %F, fetchmail encloses the addresses in single quotes ('),
500 after removing any single quotes they may contain, before the MDA
501 command is passed to the shell. Do \fINOT\fR use an MDA invocation
502 like "sendmail \-i \-t" that dispatches on the contents of To/Cc/Bcc, it
503 will create mail loops and bring the just wrath of many postmasters
504 down upon your head. Also, do \fInot\fR try to combine multidrop
505 mode with an MDA such as maildrop or procmail that can only accept one
506 address; you will lose mail.
508 A word of warning: the well-known
510 package is very hard to configure properly, it has a very nasty "fall
511 through to the next rule" behavior on delivery errors (even temporary
512 ones, such as out of disk space if another user's mail daemon copies the
513 mailbox around to purge old messages), so your mail will end up in the
514 wrong mailbox sooner or later. The proper procmail configuration is
515 outside the scope of this document though. Using
517 is usually much easier, and many users find the filter syntax used by
518 maildrop easier to understand.
523 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
524 host and port \fBmust\fR be explicitly specified on each host in the
525 smtphost hunt list (see above) if this option is selected; the default
526 port 25 will (in accordance with RFC 2033) not be accepted.
528 .B \-\-bsmtp <filename>
530 Append fetched mail to a BSMTP file. This simply contains the SMTP
531 commands that would normally be generated by fetchmail when passing
532 mail to an SMTP listener daemon. An argument of '\-' causes the mail
533 to be written to standard output. Note that fetchmail's
534 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
535 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
536 MAILBOXES below apply.
537 .SS Resource Limit Control Options
539 .B \-l <maxbytes> | \-\-limit <maxbytes>
540 (Keyword: limit) Takes a maximum octet size argument. Messages larger
541 than this size will not be fetched and will be left on the server (in
542 foreground sessions, the progress messages will note that they are
543 "oversized"). If the fetch protocol permits (in particular, under
544 IMAP or POP3 without the fetchall option) the message will not be
547 An explicit \-\-limit of 0 overrides any limits set in your
548 run control file. This option is intended for those needing to
549 strictly control fetch time due to expensive and variable phone rates.
551 Combined with \-\-limitflush, it can be used to delete oversized
552 messages waiting on a server. In daemon mode, oversize notifications
553 are mailed to the calling user (see the \-\-warnings option). This
554 option does not work with ETRN or ODMR.
556 .B \-w <interval> | \-\-warnings <interval>
558 Takes an interval in seconds. When you call
560 with a 'limit' option in daemon mode, this controls the interval at
561 which warnings about oversized messages are mailed to the calling user
562 (or the user specified by the 'postmaster' option). One such
563 notification is always mailed at the end of the the first poll that
564 the oversized message is detected. Thereafter, re-notification is
565 suppressed until after the warning interval elapses (it will take
566 place at the end of the first following poll).
568 .B \-b <count> | \-\-batchlimit <count>
569 (Keyword: batchlimit)
570 Specify the maximum number of messages that will be shipped to an SMTP
571 listener before the connection is deliberately torn down and rebuilt
572 (defaults to 0, meaning no limit). An explicit \-\-batchlimit of 0
573 overrides any limits set in your run control file. While
574 \fBsendmail\fR(8) normally initiates delivery of a message immediately
575 after receiving the message terminator, some SMTP listeners are not so
576 prompt. MTAs like \fIsmail\fR(8) may wait till the
577 delivery socket is shut down to deliver. This may produce annoying
578 delays when \fIfetchmail\fR is processing very large batches. Setting
579 the batch limit to some nonzero size will prevent these delays. This
580 option does not work with ETRN or ODMR.
582 .B \-B <number> | \-\-fetchlimit <number>
583 (Keyword: fetchlimit)
584 Limit the number of messages accepted from a given server in a single
585 poll. By default there is no limit. An explicit \-\-fetchlimit of 0
586 overrides any limits set in your run control file.
587 This option does not work with ETRN or ODMR.
589 .B \-\-fetchsizelimit <number>
590 (Keyword: fetchsizelimit)
591 Limit the number of sizes of messages accepted from a given server in
592 a single transaction. This option is useful in reducing the delay in
593 downloading the first mail when there are too many mails in the
594 mailbox. By default, the limit is 100. If set to 0, sizes of all
595 messages are downloaded at the start.
596 This option does not work with ETRN or ODMR. For POP3, the only valid
599 .B \-\-fastuidl <number>
601 Do a binary instead of linear search for the first unseen UID. Binary
602 search avoids downloading the UIDs of all mails. This saves time
603 (especially in daemon mode) where downloading the same set of UIDs in
604 each poll is a waste of bandwidth. The number 'n' indicates how rarely
605 a linear search should be done. In daemon mode, linear search is used
606 once followed by binary searches in 'n-1' polls if 'n' is greater than
607 1; binary search is always used if 'n' is 1; linear search is always
608 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
609 1; otherwise linear search is used.
610 This option works with POP3 only.
612 .B \-e <count> | \-\-expunge <count>
614 Arrange for deletions to be made final after a given number of
615 messages. Under POP2 or POP3, fetchmail cannot make deletions final
616 without sending QUIT and ending the session -- with this option on,
617 fetchmail will break a long mail retrieval session into multiple
618 sub-sessions, sending QUIT after each sub-session. This is a good
619 defense against line drops on POP3 servers that do not do the
620 equivalent of a QUIT on hangup. Under IMAP,
622 normally issues an EXPUNGE command after each deletion in order to
623 force the deletion to be done immediately. This is safest when your
624 connection to the server is flaky and expensive, as it avoids
625 resending duplicate mail after a line hit. However, on large
626 mailboxes the overhead of re-indexing after every message can slam the
627 server pretty hard, so if your connection is reliable it is good to do
628 expunges less frequently. Also note that some servers enforce a delay
629 of a few seconds after each quit, so fetchmail may not be able to get
630 back in immediately after an expunge -- you may see "lock busy" errors
631 if this happens. If you specify this option to an integer N,
634 to only issue expunges on every Nth delete. An argument of zero
635 suppresses expunges entirely (so no expunges at all will be done until
636 the end of run). This option does not work with ETRN or ODMR.
637 .SS Authentication Options
639 .B \-u <name> | \-\-user <name> | \-\-username <name>
640 (Keyword: user[name])
641 Specifies the user identification to be used when logging in to the mailserver.
642 The appropriate user identification is both server and user-dependent.
643 The default is your login name on the client machine that is running
645 See USER AUTHENTICATION below for a complete description.
647 .B \-I <specification> | \-\-interface <specification>
649 Require that a specific interface device be up and have a specific local
650 or remote IPv4 (IPv6 is not supported by this option yet) address (or
651 range) before polling. Frequently \fIfetchmail\fP
652 is used over a transient point-to-point TCP/IP link established directly
653 to a mailserver via SLIP or PPP. That is a relatively secure channel.
654 But when other TCP/IP routes to the mailserver exist (e.g. when the link
655 is connected to an alternate ISP), your username and password may be
656 vulnerable to snooping (especially when daemon mode automatically polls
657 for mail, shipping a clear password over the net at predictable
658 intervals). The \-\-interface option may be used to prevent this. When
659 the specified link is not up or is not connected to a matching IP
660 address, polling will be skipped. The format is:
663 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
666 The field before the first slash is the interface name (i.e. sl0, ppp0
667 etc.). The field before the second slash is the acceptable IP address.
668 The field after the second slash is a mask which specifies a range of
669 IP addresses to accept. If no mask is present 255.255.255.255 is
670 assumed (i.e. an exact match). This option is currently only supported
671 under Linux and FreeBSD. Please see the
673 section for below for FreeBSD specific information.
675 Note that this option may be removed from a future fetchmail version.
677 .B \-M <interface> | \-\-monitor <interface>
679 Daemon mode can cause transient links which are automatically taken down
680 after a period of inactivity (e.g. PPP links) to remain up
681 indefinitely. This option identifies a system TCP/IP interface to be
682 monitored for activity. After each poll interval, if the link is up but
683 no other activity has occurred on the link, then the poll will be
684 skipped. However, when fetchmail is woken up by a signal, the
685 monitor check is skipped and the poll goes through unconditionally.
686 This option is currently only supported under Linux and FreeBSD.
691 options to work for non root users under FreeBSD, the fetchmail binary
692 must be installed SGID kmem. This would be a security hole, but
693 fetchmail runs with the effective GID set to that of the kmem group
695 when interface data is being collected.
697 Note that this option may be removed from a future fetchmail version.
700 (Keyword: auth[enticate])
701 This option permits you to specify an authentication type (see USER
702 AUTHENTICATION below for details). The possible values are \fBany\fR,
703 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
704 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
705 \fBcram\-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
706 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
707 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
708 KERBEROS\ 5); then it looks for methods that mask your password
709 (CRAM-MD5, X\-OTP - note that NTLM and MSN are not autoprobed for POP3
710 and MSN is only supported for POP3); and only if the server doesn't
711 support any of those will it ship your password en clair. Other values
712 may be used to force various authentication methods
713 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
714 Any value other than \fBpassword\fR, \fBcram\-md5\fR, \fBntlm\fR,
715 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
716 password. Specify \fBssh\fR when you are using an end-to-end secure
717 connection such as an ssh tunnel; specify \fBgssapi\fR or
718 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
719 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
720 authentication. This option does not work with ETRN.
721 .SS Miscellaneous Options
723 .B \-f <pathname> | \-\-fetchmailrc <pathname>
724 Specify a non-default name for the
726 run control file. The pathname argument must be either "-" (a single
727 dash, meaning to read the configuration from standard input) or a
728 filename. Unless the \-\-version option is also on, a named file
729 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
732 .B \-i <pathname> | \-\-idfile <pathname>
734 Specify an alternate name for the .fetchids file used to save POP3
735 UIDs. NOTE: since fetchmail 6.3.0, write access to the directory
736 containing the idfile is required, as fetchmail writes a temporary file
737 and renames it into the place of the real idfile only if the temporary
738 file has been written successfully. This avoids the truncation of
739 idfiles when running out of disk space.
741 .B \-n | \-\-norewrite
742 (Keyword: no rewrite)
745 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply\-To) in
746 fetched mail so that any mail IDs local to the server are expanded to
747 full addresses (@ and the mailserver hostname are appended). This enables
748 replies on the client to get addressed correctly (otherwise your
749 mailer might think they should be addressed to local users on the
750 client machine!). This option disables the rewrite. (This option is
751 provided to pacify people who are paranoid about having an MTA edit
752 mail headers and want to know they can prevent it, but it is generally
753 not a good idea to actually turn off rewrite.)
754 When using ETRN or ODMR, the rewrite option is ineffective.
756 .B \-E <line> | \-\-envelope <line>
757 (Keyword: envelope; Multidrop only)
759 In the configuration file, an enhanced syntax is used:
761 .B envelope [<count>] <line>
763 This option changes the header
765 assumes will carry a copy of the mail's envelope address. Normally
766 this is 'X\-Envelope\-To', but as this header is not standard, practice
767 varies. See the discussion of multidrop address handling below. As a
768 special case, 'envelope "Received"' enables parsing of sendmail-style
769 Received lines. This is the default, and it should not be necessary
770 unless you have globally disabled Received parsing with 'no envelope'
771 in the \fI.fetchmailrc\fR file.
773 The optional count argument (only available in the configuration file)
774 determines how many header lines of this kind are skipped. A count of 1
775 means: skip the first, take the second. A count of 2 means: skip the
776 first and second, take the third, and so on.
778 .B \-Q <prefix> | \-\-qvirtual <prefix>
779 (Keyword: qvirtual; Multidrop only)
780 The string prefix assigned to this option will be removed from the user
781 name found in the header specified with the \fIenvelope\fR option
782 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
783 if either is applicable). This option is useful if you are using
785 to collect the mail for an entire domain and your ISP (or your mail
786 redirection provider) is using qmail.
787 One of the basic features of qmail is the
791 message header. Whenever qmail delivers a message to a local mailbox
792 it puts the username and hostname of the envelope recipient on this
793 line. The major reason for this is to prevent mail loops. To set up
794 qmail to batch mail for a disconnected site the ISP-mailhost will have
795 normally put that site in its 'Virtualhosts' control file so it will
796 add a prefix to all mail addresses for this site. This results in mail
797 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
798 sent to 'username\&@\&userhost.userdom.dom.com' having a
799 \&'Delivered\-To:' line of the form:
801 Delivered\-To: mbox\-userstr\-username\&@\&userhost.example.com
803 The ISP can make the 'mbox\-userstr\-' prefix anything they choose
804 but a string matching the user host name is likely.
805 By using the option 'envelope Delivered\-To:' you can make fetchmail reliably
806 identify the original envelope recipient, but you have to strip the
807 \&'mbox\-userstr\-' prefix to deliver to the correct user.
808 This is what this option is for.
813 file, interpret any command-line options specified, and dump a
814 configuration report to standard output. The configuration report is
815 a data structure assignment in the language Python. This option
816 is meant to be used with an interactive
824 Removed before version 6.3.0, the required underlying inet6_apps library
825 had been discontinued and is no longer available.
827 .SH USER AUTHENTICATION AND ENCRYPTION
828 All modes except ETRN require authentication of the client to the server.
829 Normal user authentication in
831 is very much like the authentication mechanism of
833 The correct user-id and password depend upon the underlying security
834 system at the mailserver.
836 If the mailserver is a Unix machine on which you have an ordinary user
837 account, your regular login name and password are used with
839 If you use the same login name on both the server and the client machines,
840 you needn't worry about specifying a user-id with the
842 option -- the default behavior is to use your login name on the
843 client machine as the user-id on the server machine. If you use a
844 different login name on the server machine, specify that login name
847 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
852 fetchmail \-u jsmith mailgrunt
854 The default behavior of
856 is to prompt you for your mailserver password before the connection is
857 established. This is the safest way to use
859 and ensures that your password will not be compromised. You may also specify
860 your password in your
862 file. This is convenient when using
864 in daemon mode or with scripts.
865 .SS Using netrc files
867 If you do not specify a password, and
869 cannot extract one from your
871 file, it will look for a
873 file in your home directory before requesting one interactively; if an
874 entry matching the mailserver is found in that file, the password will
875 be used. Fetchmail first looks for a match on poll name; if it finds none,
876 it checks for a match on via name. See the
878 man page for details of the syntax of the
880 file. To show a practical example, a .netrc might look like
884 machine hermes.example.org
889 You can repeat this block with different user information if you need to
890 provide more than one password.
892 This feature may allow you to avoid duplicating password
893 information in more than one file.
895 On mailservers that do not provide ordinary user accounts, your user-id and
896 password are usually assigned by the server administrator when you apply for
897 a mailbox on the server. Contact your server administrator if you don't know
898 the correct user-id and password for your mailbox account.
901 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
902 independent authentication using the
904 file on the mailserver side. Under this RPOP variant, a fixed
905 per-user ID equivalent to a password was sent in clear over a link to
906 a reserved port, with the command RPOP rather than PASS to alert the
907 server that it should do special checking. RPOP is supported
910 (you can specify 'protocol RPOP' to have the program send 'RPOP'
911 rather than 'PASS') but its use is strongly discouraged. This
912 facility was vulnerable to spoofing and was withdrawn in RFC1460.
914 RFC1460 introduced APOP authentication. In this variant of POP3,
915 you register an APOP password on your server host (the program
916 to do this with on the server is probably called \fIpopauth\fR(8)). You
917 put the same password in your
921 logs in, it sends a cryptographically secure hash of your password and
922 the server greeting time to the server, which can verify it by
923 checking its authorization database.
924 .SS Alternate authentication forms
926 If your \fIfetchmail\fR was built with Kerberos support and you specify
927 Kerberos authentication (either with \-\-auth or the \fI.fetchmailrc\fR
928 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
929 ticket from the mailserver at the start of each query. Note: if
930 either the pollname or via name is 'hesiod', fetchmail will try to use
931 Hesiod to look up the mailserver.
933 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
934 expect the server to have RFC1731- or RFC1734-conforming GSSAPI
935 capability, and will use it. Currently this has only been tested over
936 Kerberos V, so you're expected to already have a ticket-granting
937 ticket. You may pass a username different from your principal name
938 using the standard \fB\-\-user\fR command or by the \fI.fetchmailrc\fR
941 If your IMAP daemon returns the PREAUTH response in its greeting line,
942 fetchmail will notice this and skip the normal authentication step.
943 This can be useful, e.g. if you start imapd explicitly using ssh.
944 In this case you can declare the authentication value 'ssh' on that
945 site entry to stop \fI.fetchmail\fR from asking you for a password
948 If you are using POP3, and the server issues a one-time-password
949 challenge conforming to RFC1938, \fIfetchmail\fR will use your
950 password as a pass phrase to generate the required response. This
951 avoids sending secrets over the net unencrypted.
953 Compuserve's RPA authentication (similar to APOP) is supported. If you
954 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
955 authentication instead of sending over the password en clair if it
956 detects "@compuserve.com" in the hostname.
958 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
959 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
960 will try to perform an NTLM authentication (instead of sending over the
961 password en clair) whenever the server returns AUTH=NTLM in its
962 capability response. Specify a user option value that looks like
963 \&'user@domain': the part to the left of the @ will be passed as the
964 username and the part to the right as the NTLM domain.
965 .SS Secure Socket Layers (SSL)
967 You can access SSL encrypted services by specifying the \-\-ssl option.
968 You can also do this using the "ssl" user option in the .fetchmailrc
969 file. With SSL encryption enabled, queries are initiated over a connection
970 after negotiating an SSL session. Some services, such as POP3 and IMAP,
971 have different well known ports defined for the SSL encrypted services.
972 The encrypted ports will be selected automatically when SSL is enabled and
973 no explicit port is specified.
975 When connecting to an SSL encrypted server, the server presents a certificate
976 to the client for validation. The certificate is checked to verify that
977 the common name in the certificate matches the name of the server being
978 contacted and that the effective and expiration dates in the certificate
979 indicate that it is currently valid. If any of these checks fail, a warning
980 message is printed, but the connection continues. The server certificate
981 does not need to be signed by any specific Certifying Authority and may
982 be a "self-signed" certificate.
984 Some SSL encrypted servers may request a client side certificate. A client
985 side public SSL certificate and private SSL key may be specified. If
986 requested by the server, the client certificate is sent to the server for
987 validation. Some servers may require a valid client certificate and may
988 refuse connections if a certificate is not provided or if the certificate
989 is not valid. Some servers may require client side certificates be signed
990 by a recognized Certifying Authority. The format for the key files and
991 the certificate files is that required by the underlying SSL libraries
992 (OpenSSL in the general case).
994 A word of care about the use of SSL: While above mentioned
995 setup with self-signed server certificates retrieved over the wires
996 can protect you from a passive eavesdropper it doesn't help against an
997 active attacker. It's clearly an improvement over sending the
998 passwords in clear but you should be aware that a man-in-the-middle
999 attack is trivially possible (in particular with tools such as dsniff,
1000 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
1001 below for some examples) is preferable if you care seriously about the
1002 security of your mailbox.
1006 also supports authentication to the ESMTP server on the client side
1007 according to RFC 2554. You can specify a name/password pair to be
1008 used with the keywords 'esmtpname' and 'esmtppassword'; the former
1009 defaults to the username of the calling user.
1013 .B \-\-daemon <interval>
1018 in daemon mode. You must specify a numeric argument which is a
1019 polling interval in seconds.
1023 puts itself in background and runs forever, querying each specified
1024 host and then sleeping for the given polling interval.
1030 will, therefore, poll all the hosts described in your
1032 file (except those explicitly excluded with the 'skip' verb) once
1033 every fifteen minutes.
1035 It is possible to set a polling interval
1038 file by saying 'set daemon <interval>', where <interval> is an
1039 integer number of seconds. If you do this, fetchmail will always
1040 start in daemon mode unless you override it with the command-line
1041 option \-\-daemon 0 or \-d0.
1043 Only one daemon process is permitted per user; in daemon mode,
1045 makes a per-user lockfile to guarantee this.
1047 Normally, calling fetchmail with a daemon in the background sends a
1048 wake-up signal to the daemon, forcing it to poll mailservers
1049 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1050 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1051 flags indicating that connections have wedged due to failed
1052 authentication or multiple timeouts.
1056 will kill a running daemon process instead of waking it up (if there
1057 is no such process, \fIfetchmail\fP will notify you.
1058 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1059 will kill the running daemon process and then quit. Otherwise,
1060 \fIfetchmail\fP will first kill a running daemon process and then
1061 continue running with the other options.
1066 .B \-\-logfile <filename>
1067 option (keyword: set logfile) is only effective when fetchmail is
1068 detached. This option allows you to redirect status messages
1069 into a specified logfile (follow the option with the logfile name). The
1070 logfile is opened for append, so previous messages aren't deleted. This
1071 is primarily useful for debugging configurations.
1075 option (keyword: set syslog) allows you to redirect status and error
1076 messages emitted to the
1078 system daemon if available.
1079 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1080 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1081 This option is intended for logging status and error messages which
1082 indicate the status of the daemon and the results while fetching mail
1084 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1085 file are still written to stderr, or to the specified log file.
1088 option turns off use of
1090 assuming it's turned on in the
1095 .B \-\-logfile <file>
1102 option suppresses backgrounding and detachment of the
1103 daemon process from its control terminal. This is useful
1104 for debugging or when fetchmail runs as the child of a supervisor
1109 Note that this also causes the logfile option to be
1110 ignored (though perhaps it shouldn't).
1112 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1113 transient errors (such as DNS failures or sendmail delivery refusals)
1114 may force the fetchall option on for the duration of the next polling
1115 cycle. This is a robustness feature. It means that if a message is
1116 fetched (and thus marked seen by the mailserver) but not delivered
1117 locally due to some transient error, it will be re-fetched during the
1118 next poll cycle. (The IMAP logic doesn't delete messages until
1119 they're delivered, so this problem does not arise.)
1121 If you touch or change the
1123 file while fetchmail is running in daemon mode, this will be detected
1124 at the beginning of the next poll cycle. When a changed
1126 is detected, fetchmail rereads it and restarts from scratch (using
1127 exec(2); no state information is retained in the new instance). Note also
1128 that if you break the
1130 file's syntax, the new instance will softly and silently vanish away
1133 .SH ADMINISTRATIVE OPTIONS
1136 .B \-\-postmaster <name>
1137 option (keyword: set postmaster) specifies the last-resort username to
1138 which multidrop mail is to be forwarded if no matching local recipient
1139 can be found. It is also used as destination of undeliverable mail if
1140 the 'bouncemail' global option is off and additionally for spam-blocked
1141 mail if the 'bouncemail' global option is off and the 'spambounce'
1142 global option is on. This option defaults to the user who invoked
1144 If the invoking user is root, then the default of this option is
1145 the user 'postmaster'. Setting postmaster to the empty string causes
1146 such mail as described above to be discarded - this however is usually a
1148 See also the description of the 'FETCHMAILUSER' environment variable in
1149 the ENVIRONMENT section below.
1153 behaves like the "set no bouncemail" global option, which see.
1157 option (keyword: set invisible) tries to make fetchmail invisible.
1158 Normally, fetchmail behaves like any other MTA would -- it generates a
1159 Received header into each message describing its place in the chain of
1160 transmission, and tells the MTA it forwards to that the mail came from
1161 the machine fetchmail itself is running on. If the invisible option
1162 is on, the Received header is suppressed and fetchmail tries to spoof
1163 the MTA it forwards to into thinking it came directly from the
1168 option (keyword: set showdots) forces fetchmail to show progress dots
1169 even if the current tty is not stdout (for example logfiles).
1170 Starting with fetchmail version 5.3.0,
1171 progress dots are only shown on stdout by default.
1175 option, you can ask fetchmail to add information to the Received
1176 header on the form "polling {label} account {user}", where {label} is
1177 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1178 and {user} is the username which is used to log on to the mail
1179 server. This header can be used to make filtering email where no
1180 useful header information is available and you want mail from
1181 different accounts sorted into different mailboxes (this could, for
1182 example, occur if you have an account on the same server running a
1183 mailing list, and are subscribed to the list using that account). The
1184 default is not adding any such header. In
1186 this is called 'tracepolls'.
1188 .SH RETRIEVAL FAILURE MODES
1189 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1190 bulletproof. In normal operation forwarding to port 25, no message is
1191 ever deleted (or even marked for deletion) on the host until the SMTP
1192 listener on the client side has acknowledged to \fIfetchmail\fR that
1193 the message has been either accepted for delivery or rejected due to a
1196 When forwarding to an MDA, however, there is more possibility
1197 of error. Some MDAs are 'safe' and reliably return a nonzero status
1198 on any delivery error, even one due to temporary resource limits.
1201 program is like this; so are most programs designed as mail transport
1204 including the sendmail wrapper of Postfix and
1206 These programs give back a reliable positive acknowledgement and
1207 can be used with the mda option with no risk of mail loss. Unsafe
1208 MDAs, though, may return 0 even on delivery failure. If this
1209 happens, you will lose mail.
1211 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1212 messages, leaving untouched (and undeleted) messages you have already
1213 read directly on the server (or fetched with a previous \fIfetchmail
1214 --keep\fR). But you may find that messages you've already read on the
1215 server are being fetched (and deleted) even when you don't specify
1216 --all. There are several reasons this can happen.
1218 One could be that you're using POP2. The POP2 protocol includes no
1219 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1220 must treat all messages as new all the time. But POP2 is obsolete, so
1223 A potential POP3 problem might be servers that insert messages
1224 in the middle of mailboxes (some VMS implementations of mail are
1225 rumored to do this). The \fIfetchmail\fR code assumes that new
1226 messages are appended to the end of the mailbox; when this is not true
1227 it may treat some old messages as new and vice versa. Using UIDL might
1228 fix this, otherwise, consider switching to IMAP.
1230 Yet another POP3 problem is that if they can't make tempfiles in the
1231 user's home directory, some POP3 servers will hand back an
1232 undocumented response that causes fetchmail to spuriously report "No
1235 The IMAP code uses the presence or absence of the server flag \eSeen
1236 to decide whether or not a message is new. This isn't the right thing
1237 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1238 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1239 the BSD-style Status flags set by mail user agents and set the \eSeen
1240 flag from them when appropriate. All Unix IMAP servers we know of do
1241 this, though it's not specified by the IMAP RFCs. If you ever trip over
1242 a server that doesn't, the symptom will be that messages you have
1243 already read on your host will look new to the server. In this
1244 (unlikely) case, only messages you fetched with \fIfetchmail \-\-keep\fR
1245 will be both undeleted and marked old.
1247 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1248 instead, it asks the server's SMTP listener to start a queue flush
1249 to the client via SMTP. Therefore it sends only undelivered messages.
1252 Many SMTP listeners allow administrators to set up 'spam filters' that
1253 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1254 triggers this feature will elicit an SMTP response which
1255 (unfortunately) varies according to the listener.
1259 return an error code of 571.
1261 According to RFC2821, the correct thing to return in this situation is
1262 550 "Requested action not taken: mailbox unavailable" (the draft adds
1263 "[E.g., mailbox not found, no access, or command rejected for policy
1266 Older versions of the
1268 MTA return 501 "Syntax error in parameters or arguments".
1272 MTA runs 554 as an antispam response.
1275 may reject code with a 500 response (followed by an enhanced status
1276 code that contains more information).
1280 treats as antispam responses and discards
1281 the message can be set with the 'antispam' option. This is one of the
1283 three circumstance under which fetchmail ever discards mail (the others
1284 are the 552 and 553 errors described below, and the suppression of
1285 multidropped messages with a message-ID already seen).
1289 is fetching from an IMAP server, the antispam response will be detected and
1290 the message rejected immediately after the headers have been fetched,
1291 without reading the message body. Thus, you won't pay for downloading
1292 spam message bodies.
1294 By default, the list of antispam responses is empty.
1296 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1297 triggers an RFC1892/RFC1894 bounce message informing the originator that
1298 we do not accept mail from it. See also BUGS.
1300 .SH SMTP/ESMTP ERROR HANDLING
1301 Besides the spam-blocking described above, fetchmail takes special
1302 actions on the following SMTP/ESMTP error responses
1304 452 (insufficient system storage)
1305 Leave the message in the server mailbox for later retrieval.
1307 552 (message exceeds fixed maximum message size)
1308 Delete the message from the server. Send bounce-mail to the
1311 553 (invalid sending domain)
1312 Delete the message from the server. Don't even try to send
1313 bounce-mail to the originator.
1315 Other errors trigger bounce mail back to the originator. See also BUGS.
1317 .SH THE RUN CONTROL FILE
1318 The preferred way to set up fetchmail is to write a
1319 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1320 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1321 When there is a conflict between the command-line arguments and the
1322 arguments in this file, the command-line arguments take precedence.
1324 To protect the security of your passwords,
1325 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1327 will complain and exit otherwise (this check is suppressed when
1330 You may read the \fI.fetchmailrc\fR file as a list of commands to
1333 is called with no arguments.
1334 .SS Run Control Syntax
1336 Comments begin with a '#' and extend through the end of the line.
1337 Otherwise the file consists of a series of server entries or global
1338 option statements in a free-format, token-oriented syntax.
1340 There are four kinds of tokens: grammar keywords, numbers
1341 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1342 A quoted string is bounded by double quotes and may contain
1343 whitespace (and quoted digits are treated as a string). Note that
1344 quoted strings will also contain line feed characters if they run across
1345 two or more lines, unless you use a backslash to join lines (see below).
1346 An unquoted string is any whitespace-delimited token that is neither
1347 numeric, string quoted nor contains the special characters ',', ';',
1350 Any amount of whitespace separates tokens in server entries, but is
1351 otherwise ignored. You may use backslash escape sequences (\en for LF,
1352 \&\et for HT, \eb for BS, \er for CR, \e\fInnn\fP for decimal (where
1353 nnn cannot start with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for
1354 hex) to embed non-printable characters or string delimiters in strings.
1355 In quoted strings, a backslash at the very end of a line will cause the
1356 backslash itself and the line feed (LF or NL, new line) character to be
1357 ignored, so that you can wrap long strings. Without the backslash at the
1358 line end, the line feed character would become part of the string.
1361 while these resemble C-style escape sequences, they are not the same.
1362 fetchmail only supports these eight styles. C supports more escape
1363 sequences that consist of backslash (\e) and a single character, but
1364 does not support decimal codes and does not require the leading 0 in
1365 octal notation. Example: fetchmail interprets \e233 the same as \exE9
1366 (Latin small letter e with acute), where C would interpret \e233 as
1367 octal 0233 = \ex9B (CSI, control sequence introducer).
1369 Each server entry consists of one of the keywords 'poll' or 'skip',
1370 followed by a server name, followed by server options, followed by any
1371 number of user descriptions. Note: the most common cause of syntax
1372 errors is mixing up user and server options.
1374 For backward compatibility, the word 'server' is a synonym for 'poll'.
1376 You can use the noise keywords 'and', 'with',
1377 \&'has', 'wants', and 'options' anywhere in an entry to make
1378 it resemble English. They're ignored, but but can make entries much
1379 easier to read at a glance. The punctuation characters ':', ';' and
1380 \&',' are also ignored.
1383 The 'poll' verb tells fetchmail to query this host when it is run with
1384 no arguments. The 'skip' verb tells
1386 not to poll this host unless it is explicitly named on the command
1387 line. (The 'skip' verb allows you to experiment with test entries
1388 safely, or easily disable entries for hosts that are temporarily down.)
1390 .SS Keyword/Option Summary
1391 Here are the legal options. Keyword suffixes enclosed in
1392 square brackets are optional. Those corresponding to short command-line
1393 options are followed by '\-' and the appropriate option letter. If
1394 option is only relevant to a single mode of operation, it is noted as
1395 \&'s' or 'm' for singledrop- or multidrop-mode, respectively.
1397 Here are the legal global options:
1401 Keyword Opt Mode Function
1403 set daemon \-d \& T{
1404 Set a background poll interval in seconds.
1406 set postmaster \& \& T{
1407 Give the name of the last-resort mail recipient (default: user running
1408 fetchmail, "postmaster" if run by the root user)
1410 set bouncemail \& \& T{
1411 Direct error mail to the sender (default)
1413 set no bouncemail \& \& T{
1414 Direct error mail to the local postmaster (as per the 'postmaster'
1415 global option above).
1417 set no spambounce \& \& T{
1418 Do not bounce spam-blocked mail (default).
1420 set spambounce \& \& T{
1421 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1422 back to the destination as indicated by the 'bouncemail' global option.
1423 Warning: Do not use this to bounce spam back to the sender - most spam
1424 is sent with false sender address and thus this option hurts innocent
1427 set logfile \-L \& T{
1428 Name of a file to append error and status messages to.
1430 set idfile \-i \& T{
1431 Name of the file to store UID lists in.
1434 Do error logging through syslog(3).
1436 set no syslog \& \& T{
1437 Turn off error logging through syslog(3). (default)
1439 set properties \& \& T{
1440 String value that is ignored by fetchmail (may be used by extension
1445 Here are the legal server options:
1449 Keyword Opt Mode Function
1452 Specify DNS name of mailserver, overriding poll name
1454 proto[col] \-p \& T{
1455 Specify protocol (case insensitive):
1456 POP2, POP3, IMAP, APOP, KPOP
1458 local[domains] \& m T{
1459 Specify domain(s) to be regarded as local
1462 Specify TCP/IP service port (obsolete, use 'service' instead).
1465 Specify service name (a numeric value is also allowed and
1466 considered a TCP/IP port number).
1468 auth[enticate] \& \& T{
1469 Set authentication type (default 'any')
1472 Server inactivity timeout in seconds (default 300)
1475 Specify envelope-address header name
1478 Disable looking for envelope address
1481 Qmail virtual domain prefix to remove from user name
1484 Specify alternate DNS names of mailserver
1487 specify IP interface(s) that must be up for server poll to take place
1490 Specify IP address to monitor for activity
1493 Specify command through which to make server connections.
1496 Specify command through which to make listener connections.
1499 Enable DNS lookup for multidrop (default)
1502 Disable DNS lookup for multidrop
1505 Do comparison by IP address for multidrop
1507 no checkalias \& m T{
1508 Do comparison by name for multidrop (default)
1511 Force POP3 to use client-side UIDLs (recommended)
1514 Turn off POP3 use of client-side UIDLs (default)
1517 Only check this site every N poll cycles; N is a numeric argument.
1520 Add poll tracing information to the Received header
1523 Set Kerberos principal (only useful with imap and kerberos)
1526 Set name for RFC2554 authentication to the ESMTP server.
1528 esmtppassword \& \& T{
1529 Set password for RFC2554 authentication to the ESMTP server.
1533 Here are the legal user options:
1537 Keyword Opt Mode Function
1539 user[name] \-u \& T{
1540 Set remote user name
1541 (local user name if name followed by 'here')
1544 Connect local and remote user names
1547 Connect local and remote user names
1550 Specify remote account password
1553 Connect to server over the specified base protocol using SSL encryption
1556 Specify file for client side public SSL certificate
1559 Specify file for client side private SSL key
1562 Force ssl protocol for connection
1565 Specify remote folder to query
1568 Specify smtp host(s) to forward to
1570 fetchdomains \& m T{
1571 Specify domains for which mail should be fetched
1573 smtpaddress \-D \& T{
1574 Specify the domain to be put in RCPT TO lines
1577 Specify the user and domain to be put in RCPT TO lines
1580 Specify what SMTP returns are interpreted as spam-policy blocks
1583 Specify MDA for local delivery
1586 Specify BSMTP batch file to append to
1589 Command to be executed before each connection
1591 postconnect \& \& T{
1592 Command to be executed after each connection
1595 Don't delete seen messages from server
1598 Flush all seen messages before querying (DANGEROUS)
1601 Flush all oversized messages before querying
1604 Fetch all messages whether seen or not
1607 Rewrite destination addresses for reply (default)
1610 Strip carriage returns from ends of lines
1613 Force carriage returns at ends of lines
1616 Force BODY=8BITMIME to ESMTP listener
1619 Strip Status and X-Mozilla-Status lines out of incoming mail
1621 dropdelivered \& \& T{
1622 Strip Delivered-To lines out of incoming mail
1625 Convert quoted-printable to 8-bit in MIME messages
1628 Idle waiting for new messages after each poll (IMAP only)
1631 Delete seen messages from server (default)
1634 Don't flush all seen messages before querying (default)
1636 no fetchall \& \& T{
1637 Retrieve only new messages (default)
1640 Don't rewrite headers
1643 Don't strip carriage returns (default)
1646 Don't force carriage returns at EOL (default)
1648 no pass8bits \& \& T{
1649 Don't force BODY=8BITMIME to ESMTP listener (default)
1651 no dropstatus \& \& T{
1652 Don't drop Status headers (default)
1654 no dropdelivered \& \& T{
1655 Don't drop Delivered\-To headers (default)
1657 no mimedecode \& \& T{
1658 Don't convert quoted-printable to 8-bit in MIME messages (default)
1661 Don't idle waiting for new messages after each poll (IMAP only)
1664 Set message size limit
1667 Set message size warning interval
1669 batchlimit \-b \& T{
1670 Max # messages to forward in single connect
1672 fetchlimit \-B \& T{
1673 Max # messages to fetch in single connect
1675 fetchsizelimit \& \& T{
1676 Max # message sizes to fetch in single transaction
1679 Use binary search for first unseen message (POP3 only)
1682 Perform an expunge on every #th message (IMAP and POP3 only)
1685 String value is ignored by fetchmail (may be used by extension scripts)
1689 Remember that all user options must \fIfollow\fR all server options.
1691 In the .fetchmailrc file, the 'envelope' string argument may be
1692 preceded by a whitespace-separated number. This number, if specified,
1693 is the number of such headers to skip over (that is, an argument of 1
1694 selects the second header of the given type). This is sometime useful
1695 for ignoring bogus envelope headers created by an ISP's local delivery
1696 agent or internal forwards (through mail inspection systems, for
1698 .SS Keywords Not Corresponding To Option Switches
1700 The 'folder' and 'smtphost' options (unlike their command-line
1701 equivalents) can take a space- or comma-separated list of names
1704 All options correspond to the obvious command-line arguments, except
1705 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1706 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1707 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1708 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1709 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1710 idle', and 'no envelope'.
1712 The 'via' option is for if you want to have more
1713 than one configuration pointing at the same site. If it is present,
1714 the string argument will be taken as the actual DNS name of the
1715 mailserver host to query.
1716 This will override the argument of poll, which can then simply be a
1717 distinct label for the configuration (e.g. what you would give on the
1718 command line to explicitly query this host).
1720 The 'interval' option (which takes a numeric argument) allows you to poll a
1721 server less frequently than the basic poll interval. If you say
1722 \&'interval N' the server this option is attached to will only be
1723 queried every N poll intervals.
1725 The 'is' or 'to' keywords associate the following local (client)
1726 name(s) (or server-name to client-name mappings separated by =) with
1727 the mailserver user name in the entry. If an is/to list has '*' as
1728 its last name, unrecognized names are simply passed through.
1730 A single local name can be used to support redirecting your mail when
1731 your username on the client machine is different from your name on the
1732 mailserver. When there is only a single local name, mail is forwarded
1733 to that local username regardless of the message's Received, To, Cc,
1734 and Bcc headers. In this case
1736 never does DNS lookups.
1738 When there is more than one local name (or name mapping) the
1739 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1740 headers of retrieved mail (this is 'multidrop mode'). It looks for
1741 addresses with hostname parts that match your poll name or your 'via',
1742 \&'aka' or 'localdomains' options, and usually also for hostname parts
1743 which DNS tells it are aliases of the mailserver. See the discussion
1744 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1745 matching addresses are handled.
1747 If \fIfetchmail\fR cannot match any mailserver usernames or
1748 localdomain addresses, the mail will be bounced.
1749 Normally it will be bounced to the sender, but if the 'bouncemail'
1750 global option is off, the mail will go to the local postmaster instead.
1751 (see the 'postmaster' global option). See also BUGS.
1753 The 'dns' option (normally on) controls the way addresses from
1754 multidrop mailboxes are checked. On, it enables logic to check each
1755 host address that does not match an 'aka' or 'localdomains' declaration
1756 by looking it up with DNS. When a mailserver username is recognized
1757 attached to a matching hostname part, its local mapping is added to
1758 the list of local recipients.
1760 The 'checkalias' option (normally off) extends the lookups performed
1761 by the 'dns' keyword in multidrop mode, providing a way to cope with
1762 remote MTAs that identify themselves using their canonical name, while
1763 they're polled using an alias.
1764 When such a server is polled, checks to extract the envelope address
1767 reverts to delivery using the To/Cc/Bcc headers (See below
1768 \&'Header vs. Envelope addresses').
1769 Specifying this option instructs
1771 to retrieve all the IP addresses associated with both the poll name
1772 and the name used by the remote MTA and to do a comparison of the IP
1773 addresses. This comes in handy in situations where the remote server
1774 undergoes frequent canonical name changes, that would otherwise
1775 require modifications to the rcfile. 'checkalias' has no effect if
1776 \&'no dns' is specified in the rcfile.
1778 The 'aka' option is for use with multidrop mailboxes. It allows you
1779 to pre-declare a list of DNS aliases for a server. This is an
1780 optimization hack that allows you to trade space for speed. When
1782 while processing a multidrop mailbox, grovels through message headers
1783 looking for names of the mailserver, pre-declaring common ones can
1784 save it from having to do DNS lookups. Note: the names you give
1785 as arguments to 'aka' are matched as suffixes -- if you specify
1786 (say) 'aka netaxs.com', this will match not just a hostname
1787 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1788 (say) pop3.netaxs.com and mail.netaxs.com.
1790 The 'localdomains' option allows you to declare a list of domains
1791 which fetchmail should consider local. When fetchmail is parsing
1792 address lines in multidrop modes, and a trailing segment of a host
1793 name matches a declared local domain, that address is passed through
1794 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1797 If you are using 'localdomains', you may also need to specify 'no
1798 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1799 an envelope address from the Received line or X-Envelope-To header or
1800 whatever header has been previously set by 'envelope'. If you set 'no
1801 envelope' in the defaults entry it is possible to undo that in
1802 individual entries by using 'envelope <string>'. As a special case,
1803 \&'envelope "Received"' restores the default parsing of
1806 The \fBpassword\fR option requires a string argument, which is the password
1807 to be used with the entry's server.
1809 The 'preconnect' keyword allows you to specify a shell command to be
1810 executed just before each time
1812 establishes a mailserver connection. This may be useful if you are
1813 attempting to set up secure POP connections with the aid of
1815 If the command returns a nonzero status, the poll of that mailserver
1818 Similarly, the 'postconnect' keyword similarly allows you to specify a
1819 shell command to be executed just after each time a mailserver
1820 connection is taken down.
1822 The 'forcecr' option controls whether lines terminated by LF only are
1823 given CRLF termination before forwarding. Strictly speaking RFC821
1824 requires this, but few MTAs enforce the requirement it so this option
1825 is normally off (only one such MTA, qmail, is in significant use at
1828 The 'stripcr' option controls whether carriage returns are stripped
1829 out of retrieved mail before it is forwarded. It is normally not
1830 necessary to set this, because it defaults to 'on' (CR stripping
1831 enabled) when there is an MDA declared but 'off' (CR stripping
1832 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1833 both on, 'stripcr' will override.
1835 The 'pass8bits' option exists to cope with Microsoft mail programs that
1836 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1837 this option off (the default) and such a header present,
1839 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1840 messages actually using 8-bit ISO or KOI-8 character sets, which will
1841 be garbled by having the high bits of all characters stripped. If
1842 \&'pass8bits' is on,
1844 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1845 the listener is 8-bit-clean (as all the major ones now are) the right
1846 thing will probably result.
1848 The 'dropstatus' option controls whether nonempty Status and
1849 X-Mozilla-Status lines are retained in fetched mail (the default) or
1850 discarded. Retaining them allows your MUA to see what messages (if
1851 any) were marked seen on the server. On the other hand, it can
1852 confuse some new-mail notifiers, which assume that anything with a
1853 Status line in it has been seen. (Note: the empty Status lines
1854 inserted by some buggy POP servers are unconditionally discarded.)
1856 The 'dropdelivered' option controls whether Delivered\-To headers will
1857 be kept in fetched mail (the default) or discarded. These headers are
1858 added by Qmail and Postfix mailservers in order to avoid mail loops but
1859 may get in your way if you try to "mirror" a mailserver within the same
1860 domain. Use with caution.
1862 The 'mimedecode' option controls whether MIME messages using the
1863 quoted-printable encoding are automatically converted into pure 8-bit
1864 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1865 listener (that includes all of the major MTAs like sendmail), then
1866 this will automatically convert quoted-printable message headers and
1867 data into 8-bit data, making it easier to understand when reading
1868 mail. If your e-mail programs know how to deal with MIME messages,
1869 then this option is not needed. The mimedecode option is off by
1870 default, because doing RFC2047 conversion on headers throws away
1871 character-set information and can lead to bad results if the encoding
1872 of the headers differs from the body encoding.
1874 The 'idle' option is intended to be used with IMAP servers supporting
1875 the RFC2177 IDLE command extension, but does not strictly require it.
1876 If it is enabled, and fetchmail detects that IDLE is supported, an
1877 IDLE will be issued at the end of each poll. This will tell the IMAP
1878 server to hold the connection open and notify the client when new mail
1879 is available. If IDLE is not supported, fetchmail will simulate it by
1880 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1881 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1882 sequences. On the other hand, an IDLE connection will eat almost all
1883 of your fetchmail's time, because it will never drop the connection
1884 and allow other polls to occur unless the server times out the IDLE.
1885 It also doesn't work with multiple folders; only the first folder will
1889 The 'properties' option is an extension mechanism. It takes a string
1890 argument, which is ignored by fetchmail itself. The string argument may be
1891 used to store configuration information for scripts which require it.
1892 In particular, the output of '\-\-configdump' option will make properties
1893 associated with a user entry readily available to a Python script.
1895 .SS Miscellaneous Run Control Options
1896 The words 'here' and 'there' have useful English-like
1897 significance. Normally 'user eric is esr' would mean that
1898 mail for the remote user 'eric' is to be delivered to 'esr',
1899 but you can make this clearer by saying 'user eric there is esr here',
1900 or reverse it by saying 'user esr here is eric there'
1902 Legal protocol identifiers for use with the 'protocol' keyword are:
1906 pop2 (or POP2) (legacy, to be removed from future release)
1915 Legal authentication types are 'any', 'password', 'kerberos',
1916 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram\-md5', 'otp', 'msn'
1917 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1918 authentication by normal transmission of a password (the password may be
1919 plain text or subject to protocol-specific encryption as in APOP);
1920 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1921 start of each query instead, and send an arbitrary string as the
1922 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1923 See the description of the 'auth' keyword for more.
1925 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1926 authentication. These defaults may be overridden by later options.
1928 There are some global option statements: 'set logfile'
1929 followed by a string sets the same global specified by \-\-logfile. A
1930 command-line \-\-logfile option will override this. Note that \-\-logfile is
1931 only effective if fetchmail detaches itself from the terminal. Also,
1932 \&'set daemon' sets the poll interval as \-\-daemon does. This can be
1933 overridden by a command-line \-\-daemon option; in particular \-\-daemon\~0
1934 can be used to force foreground operation. The 'set postmaster'
1935 statement sets the address to which multidrop mail defaults if there are
1936 no local matches. Finally, 'set syslog' sends log messages to
1939 .SH DEBUGGING FETCHMAIL
1940 .SS Fetchmail crashing
1941 There are various ways in that fetchmail may "crash", i. e. stop
1942 operation suddenly and unexpectedly. A "crash" usually refers to an
1943 error condition that the software did not handle by itself. A well-known
1944 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
1945 just "segfault" for short. These can be caused by hardware or by software
1946 problems. Software-induced segfaults can usually be reproduced easily
1947 and in the same place, whereas hardware-induced segfaults can go away if
1948 the computer is rebooted, or powered off for a few hours, and can happen
1949 in random locations even if you use the software the same way.
1951 For solving hardware-induced segfaults, find the faulty component and repair or
1952 replace it. <http://www.bitwizard.nl/sig11/> may help you with details.
1954 For solving software-induced segfaults, the developers may need a "stack
1957 .SS Enabling fetchmail core dumps
1958 By default, fetchmail suppresses core dumps as these might contain
1959 passwords and other sensitive information. For debugging fetchmail
1960 crashes, obtaining a "stack backtrace" from a core dump is often the
1961 quickest way to solve the problem, and when posting your problem on a
1962 mailing list, the developers may ask you for a "backtrace".
1964 1. To get useful backtraces, fetchmail needs to be installed without
1965 getting stripped of its compilation symbols. Unfortunately, most
1966 binary packages that are installed are stripped, and core files from
1967 symbol-stripped programs are worthless. So you may need to recompile
1968 fetchmail. On many systems, you can type
1971 file `which fetchmail`
1974 to find out if fetchmail was symbol-stripped or not. If yours was
1975 unstripped, fine, proceed, if it was stripped, you need to recompile the
1976 source code first. You do not usually need to install fetchmail in order
1979 2. The shell environment that starts fetchmail needs to enable core
1980 dumps. The key is the "maximum core (file) size" that can usually be
1981 configured with a tool named "limit" or "ulimit". See the documentation
1982 for your shell for details. In the popular bash shell, "ulimit \-Sc
1983 unlimited" will allow the core dump.
1985 3. You need to tell fetchmail, too, to allow core dumps. To do
1986 this, run fetchmail with the \fB\-d0 \-v\fP options. It is often easier
1987 to also add \fB\-\-nosyslog \-N\fR as well.
1989 Finally, you need to reproduce the crash. You can just start fetchmail
1990 from the directory where you compiled it by typing \fB./fetchmail\fR,
1991 so the complete command line will start with \fB./fetchmail \-Nvd0
1992 \&\-\-nosyslog\fR and perhaps list your other options.
1994 After the crash, run your debugger to obtain the core dump. The
1995 debugger will often be GNU GDB, you can then type (adjust paths as
1996 necessary) \fBgdb ./fetchmail fetchmail.core\fR and then, after GDB
1997 has started up and read all its files, type \fBbacktrace full\fR, save
1998 the output (copy & paste will do, the backtrace will be read by a human)
1999 and then type \fBquit\fR to leave gdb.
2001 on some systems, the core
2002 files have different names, they might contain a number instead of the
2003 program name, or number and name, but it will usually have "core" as
2006 .SH INTERACTION WITH RFC 822
2007 When trying to determine the originating address of a message,
2008 fetchmail looks through headers in the following order:
2012 Resent-Sender: (ignored if it doesn't contain an @ or !)
2013 Sender: (ignored if it doesn't contain an @ or !)
2020 The originating address is used for logging, and to set the MAIL FROM
2021 address when forwarding to SMTP. This order is intended to cope
2022 gracefully with receiving mailing list messages in multidrop mode. The
2023 intent is that if a local address doesn't exist, the bounce message
2024 won't be returned blindly to the author or to the list itself, but
2025 rather to the list manager (which is less annoying).
2027 In multidrop mode, destination headers are processed as follows:
2028 First, fetchmail looks for the Received: header (or whichever one is
2029 specified by the 'envelope' option) to determine the local
2030 recipient address. If the mail is addressed to more than one recipient,
2031 the Received line won't contain any information regarding recipient addresses.
2033 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2034 lines. If they exist, they should contain the final recipients and
2035 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent\-*
2036 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2037 looked for. (The presence of a Resent\-To: is taken to imply that the
2038 person referred by the To: address has already received the original
2041 .SH CONFIGURATION EXAMPLES
2042 Note that although there are password declarations in a good many
2043 of the examples below, this is mainly for illustrative purposes.
2044 We recommend stashing account/password pairs in your $HOME/.netrc
2045 file, where they can be used not just by fetchmail but by ftp(1) and
2051 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
2057 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2060 Or, using some abbreviations:
2063 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2066 Multiple servers may be listed:
2069 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2070 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2073 Here's a version of those two with more whitespace and some noise words:
2076 poll pop.provider.net proto pop3
2077 user "jsmith", with password secret1, is "jsmith" here;
2078 poll other.provider.net proto pop2:
2079 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2082 This version is much easier to read and doesn't cost significantly
2083 more (parsing is done only once, at startup time).
2086 If you need to include whitespace in a parameter string, enclose the
2087 string in double quotes. Thus:
2090 poll mail.provider.net with proto pop3:
2091 user "jsmith" there has password "u can't krak this"
2092 is jws here and wants mda "/bin/mail"
2095 You may have an initial server description headed by the keyword
2096 \&'defaults' instead of 'poll' followed by a name. Such a record
2097 is interpreted as defaults for all queries to use. It may be overwritten
2098 by individual server descriptions. So, you could write:
2103 poll pop.provider.net
2105 poll mail.provider.net
2106 user "jjsmith" there has password "secret2"
2109 It's possible to specify more than one user per server (this is only
2110 likely to be useful when running fetchmail in daemon mode as root).
2111 The 'user' keyword leads off a user description, and every user specification
2112 in a multi-user entry must include it. Here's an example:
2115 poll pop.provider.net proto pop3 port 3111
2116 user "jsmith" with pass "secret1" is "smith" here
2117 user jones with pass "secret2" is "jjones" here keep
2120 This associates the local username 'smith' with the pop.provider.net
2121 username 'jsmith' and the local username 'jjones' with the
2122 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2123 server after download.
2125 Here's what a simple retrieval configuration for a multi-drop mailbox
2129 poll pop.provider.net:
2130 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2133 This says that the mailbox of account 'maildrop' on the server is a
2134 multi-drop box, and that messages in it should be parsed for the
2135 server user names 'golux', 'hurkle', and 'snark'. It further
2136 specifies that 'golux' and 'snark' have the same name on the
2137 client as on the server, but mail for server user 'hurkle' should be
2138 delivered to client user 'happy'.
2140 Here's an example of another kind of multidrop connection:
2143 poll pop.provider.net localdomains loonytoons.org toons.org:
2144 user maildrop with pass secret1 to * here
2147 This also says that the mailbox of account 'maildrop' on the server is
2148 a multi-drop box. It tells fetchmail that any address in the
2149 loonytoons.org or toons.org domains (including sub-domain addresses like
2150 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2151 listener without modification. Be careful of mail loops if you do this!
2153 Here's an example configuration using ssh and the plugin option. The
2154 queries are made directly on the stdin and stdout of imapd via ssh.
2155 Note that in this setup, IMAP authentication can be skipped.
2158 poll mailhost.net with proto imap:
2159 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2160 user esr is esr here
2163 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2164 Use the multiple-local-recipients feature with caution -- it can bite.
2165 All multidrop features are ineffective in ETRN and ODMR modes.
2167 Also, note that in multidrop mode duplicate mails are suppressed. A
2168 piece of mail is considered duplicate if it has the same message-ID as
2169 the message immediately preceding and more than one addressee. Such
2170 runs of messages may be generated when copies of a message addressed
2171 to multiple users are delivered to a multidrop box.
2173 .SS Header vs. Envelope addresses
2174 The fundamental problem is that by having your mailserver toss several
2175 peoples' mail in a single maildrop box, you may have thrown away
2176 potentially vital information about who each piece of mail was
2177 actually addressed to (the 'envelope address', as opposed to the
2178 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2179 at the receiving end). This 'envelope address' is the address you need
2180 in order to reroute mail properly.
2184 can deduce the envelope address. If the mailserver MTA is
2186 and the item of mail had just one recipient, the MTA will have written
2187 a 'by/for' clause that gives the envelope addressee into its Received
2188 header. But this doesn't work reliably for other MTAs, nor if there is
2189 more than one recipient. By default, \fIfetchmail\fR looks for
2190 envelope addresses in these lines; you can restore this default with
2191 \&\-E "Received" or 'envelope Received'.
2193 .B As a better alternative,
2194 some SMTP listeners and/or mail servers insert a header
2195 in each message containing a copy of the envelope addresses. This
2196 header (when it exists) is often 'X\-Original\-To', 'Delivered\-To' or
2197 \&'X\-Envelope\-To'. Fetchmail's assumption about this can be changed with
2198 the \-E or 'envelope' option. Note that writing an envelope header of
2199 this kind exposes the names of recipients (including blind-copy
2200 recipients) to all receivers of the messages, so the upstream must store
2201 one copy of the message per recipient to avoid becoming a privacy problem.
2203 Postfix, since version 2.0, writes an X\-Original\-To: header which
2204 contains a copy of the envelope as it was received.
2206 Qmail and Postfix generally write a 'Delivered\-To' header upon
2207 delivering the message to the mail spool and use it to avoid mail loops.
2208 Qmail virtual domains however will prefix the user name with a string
2209 that normally matches the user's domain. To remove this prefix you can
2210 use the \-Q or 'qvirtual' option.
2212 Sometimes, unfortunately, neither of these methods works. That is the
2213 point when you should contact your ISP and ask them to provide such an
2214 envelope header, and you should not use multidrop in this situation.
2215 When they all fail, fetchmail must fall back on the contents of To/Cc
2216 headers (Bcc headers are not available - see below) to try to determine
2217 recipient addressees -- and these are unreliable.
2218 In particular, mailing-list software often ships mail with only
2219 the list broadcast address in the To header.
2221 .B Note that a future version of fetchmail may remove To/Cc parsing!
2225 cannot deduce a recipient address that is local, and the intended
2226 recipient address was anyone other than fetchmail's invoking user,
2227 .B mail will get lost.
2228 This is what makes the multidrop feature risky without proper envelope
2231 A related problem is that when you blind-copy a mail message, the Bcc
2232 information is carried \fIonly\fR as envelope address (it's removed from
2233 the headers by the sending mail server, so fetchmail can see it only if
2234 there is an X-\Envelope\-To header). Thus, blind-copying to someone who
2235 gets mail over a fetchmail multidrop link will fail unless the the
2236 mailserver host routinely writes X\-Envelope\-To or an equivalent header
2237 into messages in your maildrop.
2239 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2240 server you're fetching from (1) stores one copy of the message per
2241 recipient in \fBIyour\fP domain and (2) records the envelope
2242 information in a special header (X\-Original\-To, Delivered\-To,
2243 X\-Envelope\-To).\fR
2245 .SS Good Ways To Use Multidrop Mailboxes
2246 Multiple local names can be used to administer a mailing list from the
2247 client side of a \fIfetchmail\fR collection. Suppose your name is
2248 \&'esr', and you want to both pick up your own mail and maintain a mailing
2249 list called (say) "fetchmail-friends", and you want to keep the alias
2250 list on your client machine.
2252 On your server, you can alias 'fetchmail\-friends' to 'esr'; then, in
2253 your \fI.fetchmailrc\fR, declare 'to esr fetchmail\-friends here'.
2254 Then, when mail including 'fetchmail\-friends' as a local address
2255 gets fetched, the list name will be appended to the list of
2256 recipients your SMTP listener sees. Therefore it will undergo alias
2257 expansion locally. Be sure to include 'esr' in the local alias
2258 expansion of fetchmail\-friends, or you'll never see mail sent only to
2259 the list. Also be sure that your listener has the "me-too" option set
2260 (sendmail's \-oXm command-line option or OXm declaration) so your name
2261 isn't removed from alias expansions in messages you send.
2263 This trick is not without its problems, however. You'll begin to see
2264 this when a message comes in that is addressed only to a mailing list
2265 you do \fInot\fR have declared as a local name. Each such message
2266 will feature an 'X\-Fetchmail\-Warning' header which is generated
2267 because fetchmail cannot find a valid local name in the recipient
2268 addresses. Such messages default (as was described above) to being
2269 sent to the local user running
2271 but the program has no way to know that that's actually the right thing.
2273 .SS Bad Ways To Abuse Multidrop Mailboxes
2274 Multidrop mailboxes and
2276 serving multiple users in daemon mode do not mix. The problem, again, is
2277 mail from mailing lists, which typically does not have an individual
2278 recipient address on it. Unless
2280 can deduce an envelope address, such mail will only go to the account
2281 running fetchmail (probably root). Also, blind-copied users are very
2282 likely never to see their mail at all.
2284 If you're tempted to use
2286 to retrieve mail for multiple users from a single mail drop via POP or
2287 IMAP, think again (and reread the section on header and envelope
2288 addresses above). It would be smarter to just let the mail sit in the
2289 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2290 SMTP sends periodically (of course, this means you have to poll more
2291 frequently than the mailserver's expiry period). If you can't arrange
2292 this, try setting up a UUCP feed.
2294 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2295 your mailserver writes an envelope-address header that fetchmail can
2296 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2299 .SS Speeding Up Multidrop Checking
2300 Normally, when multiple users are declared
2302 extracts recipient addresses as described above and checks each host
2303 part with DNS to see if it's an alias of the mailserver. If so, the
2304 name mappings described in the "to ... here" declaration are done and
2305 the mail locally delivered.
2307 This is a convenient but also slow method. To speed
2308 it up, pre-declare mailserver aliases with 'aka'; these are checked
2309 before DNS lookups are done. If you're certain your aka list contains
2311 DNS aliases of the mailserver (and all MX names pointing at it - note
2312 this may change in a future version)
2313 you can declare 'no dns' to suppress DNS lookups entirely and
2314 \fIonly\fR match against the aka list.
2317 To facilitate the use of
2319 in shell scripts, an exit code is returned to give an indication
2320 of what occurred during a given connection.
2322 The exit codes returned by
2326 One or more messages were successfully retrieved (or, if the \-c option
2327 was selected, were found waiting but not retrieved).
2329 There was no mail awaiting retrieval. (There may have been old mail still
2330 on the server but not selected for retrieval.)
2332 An error was encountered when attempting to open a socket to retrieve
2333 mail. If you don't know what a socket is, don't worry about it --
2334 just treat this as an 'unrecoverable error'. This error can also be
2335 because a protocol fetchmail wants to use is not listed in /etc/services.
2337 The user authentication step failed. This usually means that a bad
2338 user-id, password, or APOP id was specified. Or it may mean that you
2339 tried to run fetchmail under circumstances where it did not have
2340 standard input attached to a terminal and could not prompt for a
2343 Some sort of fatal protocol error was detected.
2345 There was a syntax error in the arguments to
2348 The run control file had bad permissions.
2350 There was an error condition reported by the server. Can also
2353 timed out while waiting for the server.
2355 Client-side exclusion error. This means
2357 either found another copy of itself already running, or failed in such
2358 a way that it isn't sure whether another copy is running.
2360 The user authentication step failed because the server responded "lock
2361 busy". Try again after a brief pause! This error is not implemented
2362 for all protocols, nor for all servers. If not implemented for your
2363 server, "3" will be returned instead, see above. May be returned when
2364 talking to qpopper or other servers that can respond with "lock busy"
2365 or some similar text containing the word "lock".
2369 run failed while trying to do an SMTP port open or transaction.
2371 Fatal DNS error. Fetchmail encountered an error while performing
2372 a DNS lookup at startup and could not proceed.
2374 BSMTP batch file could not be opened.
2376 Poll terminated by a fetch limit (see the \-\-fetchlimit option).
2378 Server busy indication.
2380 Server timed out during an IMAP IDLE.
2382 Internal error. You should see a message on standard error with
2387 queries more than one host, return status is 0 if \fIany\fR query
2388 successfully retrieved mail. Otherwise the returned error status is
2389 that of the last host queried.
2394 default run control file
2397 default location of file associating hosts with last message IDs seen
2398 (used only with newer RFC1939-compliant POP3 servers supporting the
2402 lock file to help prevent concurrent runs (non-root mode).
2405 your FTP run control file, which (if present) will be searched for
2406 passwords as a last resort before prompting for one interactively.
2408 /var/run/fetchmail.pid
2409 lock file to help prevent concurrent runs (root mode, Linux systems).
2412 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2415 If the FETCHMAILUSER variable is set, it is used as the name of the
2416 calling user (default local name) for purposes such as mailing error
2417 notifications. Otherwise, if either the LOGNAME or USER variable is
2418 correctly set (e.g. the corresponding UID matches the session user ID)
2419 then that name is used as the default local name. Otherwise
2420 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2421 session ID (this elaborate logic is designed to handle the case of
2422 multiple names per userid gracefully).
2424 If the environment variable FETCHMAILHOME is set to a valid and
2425 existing directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2426 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2427 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2428 directory. The .netrc file is always looked for in the the invoking
2429 user's home directory regardless of FETCHMAILHOME's setting.
2431 If the HOME_ETC variable is set, fetchmail will read
2432 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2434 If HOME_ETC and FETCHMAILHOME are set, HOME_ETC will be ignored.
2439 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2440 forces a poll of all non-skipped servers (this is in accordance with
2441 the usual conventions for system daemons).
2445 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2446 so SIGHUP due to logout can retain the default action of killing it).
2450 in foreground while a background fetchmail is running will do
2451 whichever of these is appropriate to wake it up.
2453 .SH BUGS AND KNOWN PROBLEMS
2455 The assumptions that the DNS and in particular the checkalias options
2456 make are not often sustainable. For instance, it has become uncommon for
2457 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2458 MX lookups may go away in a future release.
2460 The mda and plugin options interact badly. In order to collect error
2461 status from the MDA, fetchmail has to change its normal signal
2462 handling so that dead plugin processes don't get reaped until the end
2463 of the poll cycle. This can cause resource starvation if too many
2464 zombies accumulate. So either don't deliver to a MDA using plugins or
2465 risk being overrun by an army of undead.
2467 The \-\-interface option does not support IPv6 and it is doubtful if it
2468 ever will, since there is no portable way to query interface IPv6
2471 The RFC822 address parser used in multidrop mode chokes on some
2472 @-addresses that are technically legal but bizarre. Strange uses of
2473 quoting and embedded comments are likely to confuse it.
2475 In a message with multiple envelope headers, only the last one
2476 processed will be visible to fetchmail.
2478 Use of some of these protocols requires that the program send
2479 unencrypted passwords over the TCP/IP connection to the mailserver.
2480 This creates a risk that name/password pairs might be snaffled with a
2481 packet sniffer or more sophisticated monitoring software. Under Linux
2482 and FreeBSD, the \-\-interface option can be used to restrict polling to
2483 availability of a specific interface device with a specific local or
2484 remote IP address, but snooping is still possible if (a) either host
2485 has a network device that can be opened in promiscuous mode, or (b)
2486 the intervening network link can be tapped. We recommend the use of
2488 tunnelling to not only shroud your passwords but encrypt the entire
2491 Use of the %F or %T escapes in an mda option could open a security
2492 hole, because they pass text manipulable by an attacker to a shell
2493 command. Potential shell characters are replaced by '_' before
2494 execution. The hole is further reduced by the fact that fetchmail
2495 temporarily discards any suid privileges it may have while running the
2496 MDA. For maximum safety, however, don't use an mda command containing
2497 %F or %T when fetchmail is run from the root account itself.
2499 Fetchmail's method of sending bounces due to errors or spam-blocking and
2500 spam bounces requires that port 25 of localhost be available for sending
2505 while a background instance is running and break the syntax, the
2506 background instance will die silently. Unfortunately, it can't
2507 die noisily because we don't yet know whether syslog should be enabled.
2508 On some systems, fetchmail dies quietly even if there is no syntax
2509 error; this seems to have something to do with buggy terminal ioctl
2512 The \-f\~\- option (reading a configuration from stdin) is incompatible
2513 with the plugin option.
2515 The 'principal' option only handles Kerberos IV, not V.
2517 Interactively entered passwords are truncated after 63 characters. If
2518 you really need to use a longer password, you will have to use a
2521 A backslash as the last character of a configuration file will be
2522 flagged as a syntax error rather than ignored.
2524 Send comments, bug reports, gripes, and the like to the
2525 fetchmail\-devel list <fetchmail\-devel@lists.berlios.de>. An HTML FAQ is
2526 available at the fetchmail home page; surf to
2527 http://fetchmail.berlios.de/ or do a WWW search for pages with
2528 \&'fetchmail' in their titles.
2531 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2532 major assistance from Sunil Shetye (for code) and Rob MacGregor (for the
2535 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2536 many other people to name here have contributed code and patches.
2538 This program is descended from and replaces
2540 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2541 but some of its interface design is directly traceable to that
2544 This manual page has been improved by R.\ Hannes Beinert and H\['e]ctor
2548 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2550 The fetchmail home page: <http://fetchmail.berlios.de/>
2552 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2553 .SH APPLICABLE STANDARDS
2556 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2560 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2566 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2570 RFC 1460, RFC 1725, RFC 1939.
2579 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
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