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
176 .B \-a | \-\-all | (since v6.3.3) \-\-fetchall
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
183 or ODMR. While the \-a and \-\-all command-line and fetchall rcfile
184 options have been supported for a long time, the \-\-fetchall
185 command-line option was added in v6.3.3.
189 Keep retrieved messages on the remote mailserver. Normally, messages
190 are deleted from the folder on the mailserver after they have been retrieved.
193 option causes retrieved messages to remain in your folder on the
194 mailserver. This option does not work with ETRN or ODMR.
198 Delete retrieved messages from the remote mailserver. This
199 option forces retrieved mail to be deleted. It may be useful if
200 you have specified a default of \fBkeep\fR in your
201 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
204 POP3/IMAP only. This is a dangerous option and can cause mail loss when
205 used improperly. It deletes old (seen) messages from the mailserver
206 before retrieving new messages. Warning: This can cause mail loss if
207 you check your mail with other clients than fetchmail, and cause
208 fetchmail to delete a message it had never fetched before. Similarly, if
209 your local MTA hangs and fetchmail is aborted, the next time you run
210 fetchmail, it will delete mail that was never delivered to you. You
211 should probably not use this option in your configuration file. What you
212 probably want is the default setting: if you don't specify '\-k', then
213 fetchmail will automatically delete messages after successful
214 delivery. This option does not work with ETRN and ODMR.
217 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
218 mailserver before retrieving new messages. The size limit should be
219 separately specified with the \-\-limit option. This option does not
220 work with ETRN or ODMR.
221 .SS Protocol and Query Options
223 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
224 (Keyword: proto[col])
225 Specify the protocol to use when communicating with the remote
226 mailserver. If no protocol is specified, the default is AUTO.
228 may be one of the following:
231 Tries IMAP, POP3, and POP2 (skipping any of these for which support
232 has not been compiled in).
234 Post Office Protocol 2 (legacy, to be removed from future release)
236 Post Office Protocol 3
238 Use POP3 with old-fashioned MD5-challenge authentication.
240 Use POP3 with RPOP authentication.
242 Use POP3 with Kerberos V4 authentication on port 1109.
244 Use POP3 with Demon Internet's SDPS extensions.
246 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR automatically detects their capabilities).
248 Use the ESMTP ETRN option.
250 Use the the On-Demand Mail Relay ESMTP profile.
253 All these alternatives work in basically the same way (communicating
254 with standard server daemons to fetch mail already delivered to a
255 mailbox on the server) except ETRN and ODMR. The ETRN mode
256 allows you to ask a compliant ESMTP server (such as BSD sendmail at
257 release 8.8.0 or higher) to immediately open a sender-SMTP connection
258 to your client machine and begin forwarding any items addressed to
259 your client machine in the server's queue of undelivered mail. The
260 ODMR mode requires an ODMR-capable server and works similarly to
261 ETRN, except that it does not require the client machine to have
266 Force UIDL use (effective only with POP3). Force client-side tracking
267 of 'newness' of messages (UIDL stands for "unique ID listing" and is
268 described in RFC1939). Use with 'keep' to use a mailbox as a baby
269 news drop for a group of users. The fact that seen messages are skipped
270 is logged, unless error logging is done through syslog while running in
271 daemon mode. Note that fetchmail may automatically enable this option
272 depending on upstream server capabilities. Note also that this option
273 may be removed and forced enabled in a future fetchmail version. See
276 .B \-\-idle (since 6.3.3)
278 Enable IDLE use (effective only with IMAP). Note that this works with
279 only one folder at a given time. While the idle rcfile keyword had been
280 supported for a long time, the \-\-idle command-line option was added in
283 .B \-P <portnumber> | \-\-service <servicename>
284 (Keyword: service) Since version 6.3.0.
285 The service option permits you to specify a service name to connect to.
286 You can specify a decimal port number here, if your services database
287 lacks the required service-port assignments. See the FAQ item R12 and
288 the \-\-ssl documentation for details. This replaces the older \-\-port
291 .B \-\-port <portnumber>
293 Obsolete version of \-\-service that does not take service names.
295 this option may be removed from a future version.
297 .B \-\-principal <principal>
299 The principal option permits you to specify a service principal for
300 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
303 .B \-t <seconds> | \-\-timeout <seconds>
305 The timeout option allows you to set a server-nonresponse
306 timeout in seconds. If a mailserver does not send a greeting message
307 or respond to commands for the given number of seconds,
308 \fIfetchmail\fR will hang up on it. Without such a timeout
309 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
310 down host. This would be particularly annoying for a \fIfetchmail\fR
311 running in background. There is a default timeout which fetchmail\~\-V
312 will report. If a given connection receives too many timeouts in
313 succession, fetchmail will consider it wedged and stop retrying,
314 the calling user will be notified by email if this happens.
316 .B \-\-plugin <command>
317 (Keyword: plugin) The plugin option allows you to use an external
318 program to establish the TCP connection. This is useful if you want
319 to use socks, SSL, ssh, or need some special firewalling setup. The
320 program will be looked up in $PATH and can optionally be passed the
321 hostname and port as arguments using "%h" and "%p" respectively (note
322 that the interpolation logic is rather primitive, and these token must
323 be bounded by whitespace or beginning of string or end of string).
324 Fetchmail will write to the plugin's stdin and read from the plugin's
327 .B \-\-plugout <command>
329 Identical to the plugin option above, but this one is used for the SMTP
330 connections (which will probably not need it, so it has been separated
333 .B \-r <name> | \-\-folder <name>
335 Causes a specified non-default mail folder on the mailserver (or
336 comma-separated list of folders) to be retrieved. The syntax of the
337 folder name is server-dependent. This option is not available under
341 (Keyword: tracepolls)
342 Tell fetchmail to poll trace information in the form 'polling %s
343 account %s' to the Received line it generates, where the %s parts are
344 replaced by the user's remote name and the poll label (the Received
345 header also normally includes the server's true name). This can be
346 used to facilitate mail filtering based on the account it is being
351 Causes the connection to the mail server to be encrypted via SSL. Connect
352 to the server using the specified base protocol over a connection secured
353 by SSL. SSL support must be present at the server.
355 Note that fetchmail may still try to negotiate TLS even if this option
356 is not given. You can use the \-\-sslproto option to defeat this
357 behavior or tell fetchmail to negotiate a particular SSL protocol.
359 If no port is specified, the connection is attempted to the well known
360 port of the SSL version of the base protocol. This is generally a
361 different port than the port used by the base protocol. For IMAP, this
362 is port 143 for the clear protocol and port 993 for the SSL secured
363 protocol, for POP3, it is port 110 for the clear text and port 995 for
364 the encrypted variant.
366 If your system lacks the corresponding entries from /etc/services, see
367 the \-\-service option and specify the numeric port number as given in
368 the previous paragraph (unless your ISP had directed you to different
369 ports, which is uncommon however).
371 .B \-\-sslcert <name>
373 Specifies the file name of the client side public SSL certificate. Some
374 SSL encrypted servers may require client side keys and certificates for
375 authentication. In most cases, this is optional. This specifies
376 the location of the public key certificate to be presented to the server
377 at the time the SSL session is established. It is not required (but may
378 be provided) if the server does not require it. Some servers may
379 require it, some servers may request it but not require it, and some
380 servers may not request it at all. It may be the same file
381 as the private key (combined key and certificate file) but this is not
386 Specifies the file name of the client side private SSL key. Some SSL
387 encrypted servers may require client side keys and certificates for
388 authentication. In most cases, this is optional. This specifies
389 the location of the private key used to sign transactions with the server
390 at the time the SSL session is established. It is not required (but may
391 be provided) if the server does not require it. Some servers may
392 require it, some servers may request it but not require it, and some
393 servers may not request it at all. It may be the same file
394 as the public key (combined key and certificate file) but this is not
395 recommended. If a password is required to unlock the key, it will be
396 prompted for at the time just prior to establishing the session to the
397 server. This can cause some complications in daemon mode.
399 .B \-\-sslproto <name>
401 Forces an SSL protocol. Possible values are '\fBssl2\fR',
402 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
403 handshake does not work for your server. To defeat automatic TLSv1
404 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
405 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
410 Causes fetchmail to strictly check the server certificate against a set of
411 local trusted certificates (see the \fBsslcertpath\fR option). If the server
412 certificate is not signed by one of the trusted ones (directly or indirectly),
413 the SSL connection will fail. This checking should prevent man-in-the-middle
414 attacks against the SSL connection. Note that CRLs are seemingly not currently
415 supported by OpenSSL in certificate verification! Your system clock should
416 be reasonably accurate when using this option!
418 .B \-\-sslcertpath <directory>
419 (Keyword: sslcertpath)
420 Sets the directory fetchmail uses to look up local certificates. The default
421 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
422 it - every time you add or modify a certificate in the directory, you need
423 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
426 .B \-\-sslfingerprint <fingerprint>
427 (Keyword: sslfingerprint)
428 Specify the fingerprint of the server key (an MD5 hash of the key) in
429 hexadecimal notation with colons separating groups of two digits. The letter
430 hex digits must be in upper case. This is the default format OpenSSL uses,
431 and the one fetchmail uses to report the fingerprint when an SSL connection
432 is established. When this is specified, fetchmail will compare the server key
433 fingerprint with the given one, and the connection will fail if they do not
434 match. This can be used to prevent man-in-the-middle attacks.
436 To obtain the fingerprint of a certificate stored in the file cert.pem,
440 openssl x509 \-in cert.pem \-noout \-md5 \-fingerprint
445 .SS Delivery Control Options
447 .B \-S <hosts> | \-\-smtphost <hosts>
448 (Keyword: smtp[host])
449 Specify a hunt list of hosts to forward mail to (one or more
450 hostnames, comma-separated). Hosts are tried in list order; the first
451 one that is up becomes the forwarding target for the current run. If
452 this option is not specified, 'localhost' is used as the default.
453 Each hostname may have a port number following the host name. The
454 port number is separated from the host name by a slash; the default
455 port is "smtp". If you specify an absolute path name (beginning with
456 a /), it will be interpreted as the name of a UNIX socket accepting
457 LMTP connections (such as is supported by the Cyrus IMAP daemon)
461 \-\-smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
464 This option can be used with ODMR, and will make fetchmail a relay
465 between the ODMR server and SMTP or LMTP receiver.
467 .B \-\-fetchdomains <hosts>
468 (Keyword: fetchdomains)
469 In ETRN or ODMR mode, this option specifies the list of domains the
470 server should ship mail for once the connection is turned around. The
471 default is the FQDN of the machine running
474 .B \-D <domain> | \-\-smtpaddress <domain>
475 (Keyword: smtpaddress) Specify the domain to be appended to addresses
476 in RCPT TO lines shipped to SMTP. When this is not specified, the name
477 of the SMTP server (as specified by \-\-smtphost) is used for SMTP/LMTP
478 and 'localhost' is used for UNIX socket/BSMTP.
480 .B \-\-smtpname <user@domain>
482 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
483 The default user is the current local user.
485 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
487 Specifies the list of numeric SMTP errors that are to be interpreted
488 as a spam-block response from the listener. A value of \-1 disables
489 this option. For the command-line option, the list values should
492 .B \-m <command> | \-\-mda <command>
493 (Keyword: mda) You can force mail to be passed to an MDA directly
494 (rather than forwarded to port 25) with the \-\-mda or \-m option. To
495 avoid losing mail, use this option only with MDAs like maildrop or
496 MTAs like sendmail that return a nonzero status on disk-full and other
497 resource-exhaustion errors; the nonzero status tells fetchmail that
498 delivery failed and prevents the message from being deleted off the
499 server. If \fIfetchmail\fR is running as root, it sets its user id to
500 that of the target user while delivering mail through an MDA. Some
501 possible MDAs are "/usr/sbin/sendmail \-i \-f %F \-\- %T" (\fBNote:\fR
502 some several older or vendor sendmail versions mistake \-\- for an
503 address, rather than an indicator to mark the end of the option arguments),
504 "/usr/bin/deliver" and "/usr/bin/maildrop \-d %T". Local delivery
505 addresses will be inserted into the MDA command wherever you place a
506 %T; the mail message's From address will be inserted where you place
507 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
508 both %T and %F, fetchmail encloses the addresses in single quotes ('),
509 after removing any single quotes they may contain, before the MDA
510 command is passed to the shell. Do \fINOT\fR use an MDA invocation
511 like "sendmail \-i \-t" that dispatches on the contents of To/Cc/Bcc, it
512 will create mail loops and bring the just wrath of many postmasters
513 down upon your head. Also, do \fInot\fR try to combine multidrop
514 mode with an MDA such as maildrop or procmail that can only accept one
515 address; you will lose mail.
517 A word of warning: the well-known
519 package is very hard to configure properly, it has a very nasty "fall
520 through to the next rule" behavior on delivery errors (even temporary
521 ones, such as out of disk space if another user's mail daemon copies the
522 mailbox around to purge old messages), so your mail will end up in the
523 wrong mailbox sooner or later. The proper procmail configuration is
524 outside the scope of this document though. Using
526 is usually much easier, and many users find the filter syntax used by
527 maildrop easier to understand.
532 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
533 host and port \fBmust\fR be explicitly specified on each host in the
534 smtphost hunt list (see above) if this option is selected; the default
535 port 25 will (in accordance with RFC 2033) not be accepted.
537 .B \-\-bsmtp <filename>
539 Append fetched mail to a BSMTP file. This simply contains the SMTP
540 commands that would normally be generated by fetchmail when passing
541 mail to an SMTP listener daemon. An argument of '\-' causes the mail
542 to be written to standard output. Note that fetchmail's
543 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
544 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
545 MAILBOXES below apply.
546 .SS Resource Limit Control Options
548 .B \-l <maxbytes> | \-\-limit <maxbytes>
549 (Keyword: limit) Takes a maximum octet size argument. Messages larger
550 than this size will not be fetched and will be left on the server (in
551 foreground sessions, the progress messages will note that they are
552 "oversized"). If the fetch protocol permits (in particular, under
553 IMAP or POP3 without the fetchall option) the message will not be
556 An explicit \-\-limit of 0 overrides any limits set in your
557 run control file. This option is intended for those needing to
558 strictly control fetch time due to expensive and variable phone rates.
560 Combined with \-\-limitflush, it can be used to delete oversized
561 messages waiting on a server. In daemon mode, oversize notifications
562 are mailed to the calling user (see the \-\-warnings option). This
563 option does not work with ETRN or ODMR.
565 .B \-w <interval> | \-\-warnings <interval>
567 Takes an interval in seconds. When you call
569 with a 'limit' option in daemon mode, this controls the interval at
570 which warnings about oversized messages are mailed to the calling user
571 (or the user specified by the 'postmaster' option). One such
572 notification is always mailed at the end of the the first poll that
573 the oversized message is detected. Thereafter, re-notification is
574 suppressed until after the warning interval elapses (it will take
575 place at the end of the first following poll).
577 .B \-b <count> | \-\-batchlimit <count>
578 (Keyword: batchlimit)
579 Specify the maximum number of messages that will be shipped to an SMTP
580 listener before the connection is deliberately torn down and rebuilt
581 (defaults to 0, meaning no limit). An explicit \-\-batchlimit of 0
582 overrides any limits set in your run control file. While
583 \fBsendmail\fR(8) normally initiates delivery of a message immediately
584 after receiving the message terminator, some SMTP listeners are not so
585 prompt. MTAs like \fIsmail\fR(8) may wait till the
586 delivery socket is shut down to deliver. This may produce annoying
587 delays when \fIfetchmail\fR is processing very large batches. Setting
588 the batch limit to some nonzero size will prevent these delays. This
589 option does not work with ETRN or ODMR.
591 .B \-B <number> | \-\-fetchlimit <number>
592 (Keyword: fetchlimit)
593 Limit the number of messages accepted from a given server in a single
594 poll. By default there is no limit. An explicit \-\-fetchlimit of 0
595 overrides any limits set in your run control file.
596 This option does not work with ETRN or ODMR.
598 .B \-\-fetchsizelimit <number>
599 (Keyword: fetchsizelimit)
600 Limit the number of sizes of messages accepted from a given server in
601 a single transaction. This option is useful in reducing the delay in
602 downloading the first mail when there are too many mails in the
603 mailbox. By default, the limit is 100. If set to 0, sizes of all
604 messages are downloaded at the start.
605 This option does not work with ETRN or ODMR. For POP3, the only valid
608 .B \-\-fastuidl <number>
610 Do a binary instead of linear search for the first unseen UID. Binary
611 search avoids downloading the UIDs of all mails. This saves time
612 (especially in daemon mode) where downloading the same set of UIDs in
613 each poll is a waste of bandwidth. The number 'n' indicates how rarely
614 a linear search should be done. In daemon mode, linear search is used
615 once followed by binary searches in 'n-1' polls if 'n' is greater than
616 1; binary search is always used if 'n' is 1; linear search is always
617 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
618 1; otherwise linear search is used. The default value of 'n' is 4.
619 This option works with POP3 only.
621 .B \-e <count> | \-\-expunge <count>
623 Arrange for deletions to be made final after a given number of
624 messages. Under POP2 or POP3, fetchmail cannot make deletions final
625 without sending QUIT and ending the session -- with this option on,
626 fetchmail will break a long mail retrieval session into multiple
627 sub-sessions, sending QUIT after each sub-session. This is a good
628 defense against line drops on POP3 servers that do not do the
629 equivalent of a QUIT on hangup. Under IMAP,
631 normally issues an EXPUNGE command after each deletion in order to
632 force the deletion to be done immediately. This is safest when your
633 connection to the server is flaky and expensive, as it avoids
634 resending duplicate mail after a line hit. However, on large
635 mailboxes the overhead of re-indexing after every message can slam the
636 server pretty hard, so if your connection is reliable it is good to do
637 expunges less frequently. Also note that some servers enforce a delay
638 of a few seconds after each quit, so fetchmail may not be able to get
639 back in immediately after an expunge -- you may see "lock busy" errors
640 if this happens. If you specify this option to an integer N,
643 to only issue expunges on every Nth delete. An argument of zero
644 suppresses expunges entirely (so no expunges at all will be done until
645 the end of run). This option does not work with ETRN or ODMR.
646 .SS Authentication Options
648 .B \-u <name> | \-\-user <name> | \-\-username <name>
649 (Keyword: user[name])
650 Specifies the user identification to be used when logging in to the mailserver.
651 The appropriate user identification is both server and user-dependent.
652 The default is your login name on the client machine that is running
654 See USER AUTHENTICATION below for a complete description.
656 .B \-I <specification> | \-\-interface <specification>
658 Require that a specific interface device be up and have a specific local
659 or remote IPv4 (IPv6 is not supported by this option yet) address (or
660 range) before polling. Frequently \fIfetchmail\fP
661 is used over a transient point-to-point TCP/IP link established directly
662 to a mailserver via SLIP or PPP. That is a relatively secure channel.
663 But when other TCP/IP routes to the mailserver exist (e.g. when the link
664 is connected to an alternate ISP), your username and password may be
665 vulnerable to snooping (especially when daemon mode automatically polls
666 for mail, shipping a clear password over the net at predictable
667 intervals). The \-\-interface option may be used to prevent this. When
668 the specified link is not up or is not connected to a matching IP
669 address, polling will be skipped. The format is:
672 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
675 The field before the first slash is the interface name (i.e. sl0, ppp0
676 etc.). The field before the second slash is the acceptable IP address.
677 The field after the second slash is a mask which specifies a range of
678 IP addresses to accept. If no mask is present 255.255.255.255 is
679 assumed (i.e. an exact match). This option is currently only supported
680 under Linux and FreeBSD. Please see the
682 section for below for FreeBSD specific information.
684 Note that this option may be removed from a future fetchmail version.
686 .B \-M <interface> | \-\-monitor <interface>
688 Daemon mode can cause transient links which are automatically taken down
689 after a period of inactivity (e.g. PPP links) to remain up
690 indefinitely. This option identifies a system TCP/IP interface to be
691 monitored for activity. After each poll interval, if the link is up but
692 no other activity has occurred on the link, then the poll will be
693 skipped. However, when fetchmail is woken up by a signal, the
694 monitor check is skipped and the poll goes through unconditionally.
695 This option is currently only supported under Linux and FreeBSD.
700 options to work for non root users under FreeBSD, the fetchmail binary
701 must be installed SGID kmem. This would be a security hole, but
702 fetchmail runs with the effective GID set to that of the kmem group
704 when interface data is being collected.
706 Note that this option may be removed from a future fetchmail version.
709 (Keyword: auth[enticate])
710 This option permits you to specify an authentication type (see USER
711 AUTHENTICATION below for details). The possible values are \fBany\fR,
712 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
713 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
714 \fBcram\-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
715 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
716 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
717 KERBEROS\ 5); then it looks for methods that mask your password
718 (CRAM-MD5, X\-OTP - note that NTLM and MSN are not autoprobed for POP3
719 and MSN is only supported for POP3); and only if the server doesn't
720 support any of those will it ship your password en clair. Other values
721 may be used to force various authentication methods
722 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
723 Any value other than \fBpassword\fR, \fBcram\-md5\fR, \fBntlm\fR,
724 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
725 password. Specify \fBssh\fR when you are using an end-to-end secure
726 connection such as an ssh tunnel; specify \fBgssapi\fR or
727 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
728 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
729 authentication. This option does not work with ETRN.
730 .SS Miscellaneous Options
732 .B \-f <pathname> | \-\-fetchmailrc <pathname>
733 Specify a non-default name for the
735 run control file. The pathname argument must be either "-" (a single
736 dash, meaning to read the configuration from standard input) or a
737 filename. Unless the \-\-version option is also on, a named file
738 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
741 .B \-i <pathname> | \-\-idfile <pathname>
743 Specify an alternate name for the .fetchids file used to save POP3
744 UIDs. NOTE: since fetchmail 6.3.0, write access to the directory
745 containing the idfile is required, as fetchmail writes a temporary file
746 and renames it into the place of the real idfile only if the temporary
747 file has been written successfully. This avoids the truncation of
748 idfiles when running out of disk space.
750 .B \--pidfile <pathname>
751 (Keyword: pidfile; since fetchmail v6.3.4)
752 Override the default location of the PID file. Default: see
755 .B \-n | \-\-norewrite
756 (Keyword: no rewrite)
759 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply\-To) in
760 fetched mail so that any mail IDs local to the server are expanded to
761 full addresses (@ and the mailserver hostname are appended). This enables
762 replies on the client to get addressed correctly (otherwise your
763 mailer might think they should be addressed to local users on the
764 client machine!). This option disables the rewrite. (This option is
765 provided to pacify people who are paranoid about having an MTA edit
766 mail headers and want to know they can prevent it, but it is generally
767 not a good idea to actually turn off rewrite.)
768 When using ETRN or ODMR, the rewrite option is ineffective.
770 .B \-E <line> | \-\-envelope <line>
771 (Keyword: envelope; Multidrop only)
773 In the configuration file, an enhanced syntax is used:
775 .B envelope [<count>] <line>
777 This option changes the header
779 assumes will carry a copy of the mail's envelope address. Normally
780 this is 'X\-Envelope\-To', but as this header is not standard, practice
781 varies. See the discussion of multidrop address handling below. As a
782 special case, 'envelope "Received"' enables parsing of sendmail-style
783 Received lines. This is the default, and it should not be necessary
784 unless you have globally disabled Received parsing with 'no envelope'
785 in the \fI.fetchmailrc\fR file.
787 The optional count argument (only available in the configuration file)
788 determines how many header lines of this kind are skipped. A count of 1
789 means: skip the first, take the second. A count of 2 means: skip the
790 first and second, take the third, and so on.
792 .B \-Q <prefix> | \-\-qvirtual <prefix>
793 (Keyword: qvirtual; Multidrop only)
794 The string prefix assigned to this option will be removed from the user
795 name found in the header specified with the \fIenvelope\fR option
796 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
797 if either is applicable). This option is useful if you are using
799 to collect the mail for an entire domain and your ISP (or your mail
800 redirection provider) is using qmail.
801 One of the basic features of qmail is the
805 message header. Whenever qmail delivers a message to a local mailbox
806 it puts the username and hostname of the envelope recipient on this
807 line. The major reason for this is to prevent mail loops. To set up
808 qmail to batch mail for a disconnected site the ISP-mailhost will have
809 normally put that site in its 'Virtualhosts' control file so it will
810 add a prefix to all mail addresses for this site. This results in mail
811 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
812 sent to 'username\&@\&userhost.userdom.dom.com' having a
813 \&'Delivered\-To:' line of the form:
815 Delivered\-To: mbox\-userstr\-username\&@\&userhost.example.com
817 The ISP can make the 'mbox\-userstr\-' prefix anything they choose
818 but a string matching the user host name is likely.
819 By using the option 'envelope Delivered\-To:' you can make fetchmail reliably
820 identify the original envelope recipient, but you have to strip the
821 \&'mbox\-userstr\-' prefix to deliver to the correct user.
822 This is what this option is for.
827 file, interpret any command-line options specified, and dump a
828 configuration report to standard output. The configuration report is
829 a data structure assignment in the language Python. This option
830 is meant to be used with an interactive
838 Removed before version 6.3.0, the required underlying inet6_apps library
839 had been discontinued and is no longer available.
841 .SH USER AUTHENTICATION AND ENCRYPTION
842 All modes except ETRN require authentication of the client to the server.
843 Normal user authentication in
845 is very much like the authentication mechanism of
847 The correct user-id and password depend upon the underlying security
848 system at the mailserver.
850 If the mailserver is a Unix machine on which you have an ordinary user
851 account, your regular login name and password are used with
853 If you use the same login name on both the server and the client machines,
854 you needn't worry about specifying a user-id with the
856 option -- the default behavior is to use your login name on the
857 client machine as the user-id on the server machine. If you use a
858 different login name on the server machine, specify that login name
861 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
866 fetchmail \-u jsmith mailgrunt
868 The default behavior of
870 is to prompt you for your mailserver password before the connection is
871 established. This is the safest way to use
873 and ensures that your password will not be compromised. You may also specify
874 your password in your
876 file. This is convenient when using
878 in daemon mode or with scripts.
879 .SS Using netrc files
881 If you do not specify a password, and
883 cannot extract one from your
885 file, it will look for a
887 file in your home directory before requesting one interactively; if an
888 entry matching the mailserver is found in that file, the password will
889 be used. Fetchmail first looks for a match on poll name; if it finds none,
890 it checks for a match on via name. See the
892 man page for details of the syntax of the
894 file. To show a practical example, a .netrc might look like
898 machine hermes.example.org
903 You can repeat this block with different user information if you need to
904 provide more than one password.
906 This feature may allow you to avoid duplicating password
907 information in more than one file.
909 On mailservers that do not provide ordinary user accounts, your user-id and
910 password are usually assigned by the server administrator when you apply for
911 a mailbox on the server. Contact your server administrator if you don't know
912 the correct user-id and password for your mailbox account.
915 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
916 independent authentication using the
918 file on the mailserver side. Under this RPOP variant, a fixed
919 per-user ID equivalent to a password was sent in clear over a link to
920 a reserved port, with the command RPOP rather than PASS to alert the
921 server that it should do special checking. RPOP is supported
924 (you can specify 'protocol RPOP' to have the program send 'RPOP'
925 rather than 'PASS') but its use is strongly discouraged, and support
926 will be removed from a future fetchmail version. This
927 facility was vulnerable to spoofing and was withdrawn in RFC1460.
929 RFC1460 introduced APOP authentication. In this variant of POP3,
930 you register an APOP password on your server host (the program
931 to do this with on the server is probably called \fIpopauth\fR(8)). You
932 put the same password in your
936 logs in, it sends a cryptographically secure hash of your password and
937 the server greeting time to the server, which can verify it by
938 checking its authorization database.
941 makes some efforts to make the server believe messages had not been
942 retrieved, by using the TOP command with a large number of lines when
943 possible. TOP is a command that retrieves the full header and
944 a \fIfetchmail\fP-specified amount of body lines. It is optional and
945 therefore not implemented by all servers, and some are known to
946 implement it improperly. On many servers however, the RETR command which
947 retrieves the full message with header and body, sets the "seen" flag
948 (for instance, in a web interface), whereas the TOP command does not do
952 will always use the RETR command if "fetchall" is set.
954 will also use the RETR command if "keep" is set and "uidl" is unset.
957 will use the RETR command on Maillennium POP3/PROXY
958 servers (used by Comcast) to avoid a deliberate TOP misinterpretation in
959 this server that causes message corruption.
963 will use the TOP command. This implies that in "keep" setups, "uidl"
964 must be set if "TOP" is desired.
967 that this description is true for the current version of fetchmail, but
968 the behavior may change in future versions. In particular, fetchmail may
969 prefer the RETR command because the TOP command causes much grief on
970 some servers and is only optional.
971 .SH ALTERNATE AUTHENTICATION FORMS
973 If your \fIfetchmail\fR was built with Kerberos support and you specify
974 Kerberos authentication (either with \-\-auth or the \fI.fetchmailrc\fR
975 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
976 ticket from the mailserver at the start of each query. Note: if
977 either the pollname or via name is 'hesiod', fetchmail will try to use
978 Hesiod to look up the mailserver.
980 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
981 expect the server to have RFC1731- or RFC1734-conforming GSSAPI
982 capability, and will use it. Currently this has only been tested over
983 Kerberos V, so you're expected to already have a ticket-granting
984 ticket. You may pass a username different from your principal name
985 using the standard \fB\-\-user\fR command or by the \fI.fetchmailrc\fR
988 If your IMAP daemon returns the PREAUTH response in its greeting line,
989 fetchmail will notice this and skip the normal authentication step.
990 This can be useful, e.g. if you start imapd explicitly using ssh.
991 In this case you can declare the authentication value 'ssh' on that
992 site entry to stop \fI.fetchmail\fR from asking you for a password
995 If you are using POP3, and the server issues a one-time-password
996 challenge conforming to RFC1938, \fIfetchmail\fR will use your
997 password as a pass phrase to generate the required response. This
998 avoids sending secrets over the net unencrypted.
1000 Compuserve's RPA authentication (similar to APOP) is supported. If you
1001 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
1002 authentication instead of sending over the password en clair if it
1003 detects "@compuserve.com" in the hostname.
1005 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
1006 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
1007 will try to perform an NTLM authentication (instead of sending over the
1008 password en clair) whenever the server returns AUTH=NTLM in its
1009 capability response. Specify a user option value that looks like
1010 \&'user@domain': the part to the left of the @ will be passed as the
1011 username and the part to the right as the NTLM domain.
1012 .SS Secure Socket Layers (SSL) and Transport Layer Security (TLS)
1014 You can access SSL encrypted services by specifying the \-\-ssl option.
1015 You can also do this using the "ssl" user option in the .fetchmailrc
1016 file. With SSL encryption enabled, queries are initiated over a connection
1017 after negotiating an SSL session. Some services, such as POP3 and IMAP,
1018 have different well known ports defined for the SSL encrypted services.
1019 The encrypted ports will be selected automatically when SSL is enabled and
1020 no explicit port is specified.
1022 When connecting to an SSL encrypted server, the server presents a certificate
1023 to the client for validation. The certificate is checked to verify that
1024 the common name in the certificate matches the name of the server being
1025 contacted and that the effective and expiration dates in the certificate
1026 indicate that it is currently valid. If any of these checks fail, a warning
1027 message is printed, but the connection continues. The server certificate
1028 does not need to be signed by any specific Certifying Authority and may
1029 be a "self-signed" certificate.
1031 Some SSL encrypted servers may request a client side certificate. A client
1032 side public SSL certificate and private SSL key may be specified. If
1033 requested by the server, the client certificate is sent to the server for
1034 validation. Some servers may require a valid client certificate and may
1035 refuse connections if a certificate is not provided or if the certificate
1036 is not valid. Some servers may require client side certificates be signed
1037 by a recognized Certifying Authority. The format for the key files and
1038 the certificate files is that required by the underlying SSL libraries
1039 (OpenSSL in the general case).
1041 A word of care about the use of SSL: While above mentioned
1042 setup with self-signed server certificates retrieved over the wires
1043 can protect you from a passive eavesdropper it doesn't help against an
1044 active attacker. It's clearly an improvement over sending the
1045 passwords in clear but you should be aware that a man-in-the-middle
1046 attack is trivially possible (in particular with tools such as dsniff,
1047 http://monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
1048 below for some examples) is preferable if you care seriously about the
1049 security of your mailbox.
1053 also supports authentication to the ESMTP server on the client side
1054 according to RFC 2554. You can specify a name/password pair to be
1055 used with the keywords 'esmtpname' and 'esmtppassword'; the former
1056 defaults to the username of the calling user.
1060 .B \-\-daemon <interval>
1065 in daemon mode. You must specify a numeric argument which is a
1066 polling interval in seconds.
1070 puts itself in background and runs forever, querying each specified
1071 host and then sleeping for the given polling interval.
1077 will, therefore, poll all the hosts described in your
1079 file (except those explicitly excluded with the 'skip' verb) once
1080 every fifteen minutes.
1082 It is possible to set a polling interval
1085 file by saying 'set daemon <interval>', where <interval> is an
1086 integer number of seconds. If you do this, fetchmail will always
1087 start in daemon mode unless you override it with the command-line
1088 option \-\-daemon 0 or \-d0.
1090 Only one daemon process is permitted per user; in daemon mode,
1092 makes a per-user lockfile to guarantee this.
1094 Normally, calling fetchmail with a daemon in the background sends a
1095 wake-up signal to the daemon, forcing it to poll mailservers
1096 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1097 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1098 flags indicating that connections have wedged due to failed
1099 authentication or multiple timeouts.
1103 will kill a running daemon process instead of waking it up (if there
1104 is no such process, \fIfetchmail\fP will notify you.
1105 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1106 will kill the running daemon process and then quit. Otherwise,
1107 \fIfetchmail\fP will first kill a running daemon process and then
1108 continue running with the other options.
1113 .B \-\-logfile <filename>
1114 option (keyword: set logfile) is only effective when fetchmail is
1115 detached. This option allows you to redirect status messages
1116 into a specified logfile (follow the option with the logfile name). The
1117 logfile is opened for append, so previous messages aren't deleted. This
1118 is primarily useful for debugging configurations.
1122 option (keyword: set syslog) allows you to redirect status and error
1123 messages emitted to the
1125 system daemon if available.
1126 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1127 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1128 This option is intended for logging status and error messages which
1129 indicate the status of the daemon and the results while fetching mail
1131 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1132 file are still written to stderr, or to the specified log file.
1135 option turns off use of
1137 assuming it's turned on in the
1142 .B \-\-logfile <file>
1149 option suppresses backgrounding and detachment of the
1150 daemon process from its control terminal. This is useful
1151 for debugging or when fetchmail runs as the child of a supervisor
1156 Note that this also causes the logfile option to be
1157 ignored (though perhaps it shouldn't).
1159 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1160 transient errors (such as DNS failures or sendmail delivery refusals)
1161 may force the fetchall option on for the duration of the next polling
1162 cycle. This is a robustness feature. It means that if a message is
1163 fetched (and thus marked seen by the mailserver) but not delivered
1164 locally due to some transient error, it will be re-fetched during the
1165 next poll cycle. (The IMAP logic doesn't delete messages until
1166 they're delivered, so this problem does not arise.)
1168 If you touch or change the
1170 file while fetchmail is running in daemon mode, this will be detected
1171 at the beginning of the next poll cycle. When a changed
1173 is detected, fetchmail rereads it and restarts from scratch (using
1174 exec(2); no state information is retained in the new instance). Note also
1175 that if you break the
1177 file's syntax, the new instance will softly and silently vanish away
1180 .SH ADMINISTRATIVE OPTIONS
1183 .B \-\-postmaster <name>
1184 option (keyword: set postmaster) specifies the last-resort username to
1185 which multidrop mail is to be forwarded if no matching local recipient
1186 can be found. It is also used as destination of undeliverable mail if
1187 the 'bouncemail' global option is off and additionally for spam-blocked
1188 mail if the 'bouncemail' global option is off and the 'spambounce'
1189 global option is on. This option defaults to the user who invoked
1191 If the invoking user is root, then the default of this option is
1192 the user 'postmaster'. Setting postmaster to the empty string causes
1193 such mail as described above to be discarded - this however is usually a
1195 See also the description of the 'FETCHMAILUSER' environment variable in
1196 the ENVIRONMENT section below.
1200 behaves like the "set no bouncemail" global option, which see.
1204 option (keyword: set invisible) tries to make fetchmail invisible.
1205 Normally, fetchmail behaves like any other MTA would -- it generates a
1206 Received header into each message describing its place in the chain of
1207 transmission, and tells the MTA it forwards to that the mail came from
1208 the machine fetchmail itself is running on. If the invisible option
1209 is on, the Received header is suppressed and fetchmail tries to spoof
1210 the MTA it forwards to into thinking it came directly from the
1215 option (keyword: set showdots) forces fetchmail to show progress dots
1216 even if the current tty is not stdout (for example logfiles).
1217 Fetchmail shows the dots by default when run in nodetach mode or when
1218 daemon mode is not enabled.
1222 option, you can ask fetchmail to add information to the Received
1223 header on the form "polling {label} account {user}", where {label} is
1224 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1225 and {user} is the username which is used to log on to the mail
1226 server. This header can be used to make filtering email where no
1227 useful header information is available and you want mail from
1228 different accounts sorted into different mailboxes (this could, for
1229 example, occur if you have an account on the same server running a
1230 mailing list, and are subscribed to the list using that account). The
1231 default is not adding any such header. In
1233 this is called 'tracepolls'.
1235 .SH RETRIEVAL FAILURE MODES
1236 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1237 bulletproof. In normal operation forwarding to port 25, no message is
1238 ever deleted (or even marked for deletion) on the host until the SMTP
1239 listener on the client side has acknowledged to \fIfetchmail\fR that
1240 the message has been either accepted for delivery or rejected due to a
1243 When forwarding to an MDA, however, there is more possibility
1244 of error. Some MDAs are 'safe' and reliably return a nonzero status
1245 on any delivery error, even one due to temporary resource limits.
1248 program is like this; so are most programs designed as mail transport
1251 including the sendmail wrapper of Postfix and
1253 These programs give back a reliable positive acknowledgement and
1254 can be used with the mda option with no risk of mail loss. Unsafe
1255 MDAs, though, may return 0 even on delivery failure. If this
1256 happens, you will lose mail.
1258 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1259 messages, leaving untouched (and undeleted) messages you have already
1260 read directly on the server (or fetched with a previous \fIfetchmail
1261 --keep\fR). But you may find that messages you've already read on the
1262 server are being fetched (and deleted) even when you don't specify
1263 --all. There are several reasons this can happen.
1265 One could be that you're using POP2. The POP2 protocol includes no
1266 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1267 must treat all messages as new all the time. But POP2 is obsolete, so
1270 A potential POP3 problem might be servers that insert messages
1271 in the middle of mailboxes (some VMS implementations of mail are
1272 rumored to do this). The \fIfetchmail\fR code assumes that new
1273 messages are appended to the end of the mailbox; when this is not true
1274 it may treat some old messages as new and vice versa. Using UIDL whilst
1275 setting fastuidl 0 might fix this, otherwise, consider switching to IMAP.
1277 Yet another POP3 problem is that if they can't make tempfiles in the
1278 user's home directory, some POP3 servers will hand back an
1279 undocumented response that causes fetchmail to spuriously report "No
1282 The IMAP code uses the presence or absence of the server flag \eSeen
1283 to decide whether or not a message is new. This isn't the right thing
1284 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1285 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1286 the BSD-style Status flags set by mail user agents and set the \eSeen
1287 flag from them when appropriate. All Unix IMAP servers we know of do
1288 this, though it's not specified by the IMAP RFCs. If you ever trip over
1289 a server that doesn't, the symptom will be that messages you have
1290 already read on your host will look new to the server. In this
1291 (unlikely) case, only messages you fetched with \fIfetchmail \-\-keep\fR
1292 will be both undeleted and marked old.
1294 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1295 instead, it asks the server's SMTP listener to start a queue flush
1296 to the client via SMTP. Therefore it sends only undelivered messages.
1299 Many SMTP listeners allow administrators to set up 'spam filters' that
1300 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1301 triggers this feature will elicit an SMTP response which
1302 (unfortunately) varies according to the listener.
1306 return an error code of 571.
1308 According to RFC2821, the correct thing to return in this situation is
1309 550 "Requested action not taken: mailbox unavailable" (the draft adds
1310 "[E.g., mailbox not found, no access, or command rejected for policy
1313 Older versions of the
1315 MTA return 501 "Syntax error in parameters or arguments".
1319 MTA runs 554 as an antispam response.
1322 may reject code with a 500 response (followed by an enhanced status
1323 code that contains more information).
1327 treats as antispam responses and discards
1328 the message can be set with the 'antispam' option. This is one of the
1330 three circumstance under which fetchmail ever discards mail (the others
1331 are the 552 and 553 errors described below, and the suppression of
1332 multidropped messages with a message-ID already seen).
1336 is fetching from an IMAP server, the antispam response will be detected and
1337 the message rejected immediately after the headers have been fetched,
1338 without reading the message body. Thus, you won't pay for downloading
1339 spam message bodies.
1341 By default, the list of antispam responses is empty.
1343 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1344 triggers an RFC1892/RFC1894 bounce message informing the originator that
1345 we do not accept mail from it. See also BUGS.
1347 .SH SMTP/ESMTP ERROR HANDLING
1348 Besides the spam-blocking described above, fetchmail takes special
1349 actions on the following SMTP/ESMTP error responses
1351 452 (insufficient system storage)
1352 Leave the message in the server mailbox for later retrieval.
1354 552 (message exceeds fixed maximum message size)
1355 Delete the message from the server. Send bounce-mail to the
1358 553 (invalid sending domain)
1359 Delete the message from the server. Don't even try to send
1360 bounce-mail to the originator.
1362 Other errors trigger bounce mail back to the originator. See also BUGS.
1364 .SH THE RUN CONTROL FILE
1365 The preferred way to set up fetchmail is to write a
1366 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1367 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1368 When there is a conflict between the command-line arguments and the
1369 arguments in this file, the command-line arguments take precedence.
1371 To protect the security of your passwords,
1372 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1374 will complain and exit otherwise (this check is suppressed when
1377 You may read the \fI.fetchmailrc\fR file as a list of commands to
1380 is called with no arguments.
1381 .SS Run Control Syntax
1383 Comments begin with a '#' and extend through the end of the line.
1384 Otherwise the file consists of a series of server entries or global
1385 option statements in a free-format, token-oriented syntax.
1387 There are four kinds of tokens: grammar keywords, numbers
1388 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1389 A quoted string is bounded by double quotes and may contain
1390 whitespace (and quoted digits are treated as a string). Note that
1391 quoted strings will also contain line feed characters if they run across
1392 two or more lines, unless you use a backslash to join lines (see below).
1393 An unquoted string is any whitespace-delimited token that is neither
1394 numeric, string quoted nor contains the special characters ',', ';',
1397 Any amount of whitespace separates tokens in server entries, but is
1398 otherwise ignored. You may use backslash escape sequences (\en for LF,
1399 \&\et for HT, \eb for BS, \er for CR, \e\fInnn\fP for decimal (where
1400 nnn cannot start with a 0), \e0\fIooo\fP for octal, and \ex\fIhh\fP for
1401 hex) to embed non-printable characters or string delimiters in strings.
1402 In quoted strings, a backslash at the very end of a line will cause the
1403 backslash itself and the line feed (LF or NL, new line) character to be
1404 ignored, so that you can wrap long strings. Without the backslash at the
1405 line end, the line feed character would become part of the string.
1408 while these resemble C-style escape sequences, they are not the same.
1409 fetchmail only supports these eight styles. C supports more escape
1410 sequences that consist of backslash (\e) and a single character, but
1411 does not support decimal codes and does not require the leading 0 in
1412 octal notation. Example: fetchmail interprets \e233 the same as \exE9
1413 (Latin small letter e with acute), where C would interpret \e233 as
1414 octal 0233 = \ex9B (CSI, control sequence introducer).
1416 Each server entry consists of one of the keywords 'poll' or 'skip',
1417 followed by a server name, followed by server options, followed by any
1418 number of user descriptions. Note: the most common cause of syntax
1419 errors is mixing up user and server options.
1421 For backward compatibility, the word 'server' is a synonym for 'poll'.
1423 You can use the noise keywords 'and', 'with',
1424 \&'has', 'wants', and 'options' anywhere in an entry to make
1425 it resemble English. They're ignored, but but can make entries much
1426 easier to read at a glance. The punctuation characters ':', ';' and
1427 \&',' are also ignored.
1430 The 'poll' verb tells fetchmail to query this host when it is run with
1431 no arguments. The 'skip' verb tells
1433 not to poll this host unless it is explicitly named on the command
1434 line. (The 'skip' verb allows you to experiment with test entries
1435 safely, or easily disable entries for hosts that are temporarily down.)
1437 .SS Keyword/Option Summary
1438 Here are the legal options. Keyword suffixes enclosed in
1439 square brackets are optional. Those corresponding to short command-line
1440 options are followed by '\-' and the appropriate option letter. If
1441 option is only relevant to a single mode of operation, it is noted as
1442 \&'s' or 'm' for singledrop- or multidrop-mode, respectively.
1444 Here are the legal global options:
1448 Keyword Opt Mode Function
1450 set daemon \-d \& T{
1451 Set a background poll interval in seconds.
1453 set postmaster \& \& T{
1454 Give the name of the last-resort mail recipient (default: user running
1455 fetchmail, "postmaster" if run by the root user)
1457 set bouncemail \& \& T{
1458 Direct error mail to the sender (default)
1460 set no bouncemail \& \& T{
1461 Direct error mail to the local postmaster (as per the 'postmaster'
1462 global option above).
1464 set no spambounce \& \& T{
1465 Do not bounce spam-blocked mail (default).
1467 set spambounce \& \& T{
1468 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1469 back to the destination as indicated by the 'bouncemail' global option.
1470 Warning: Do not use this to bounce spam back to the sender - most spam
1471 is sent with false sender address and thus this option hurts innocent
1474 set logfile \-L \& T{
1475 Name of a file to append error and status messages to.
1477 set idfile \-i \& T{
1478 Name of the file to store UID lists in.
1481 Do error logging through syslog(3).
1483 set no syslog \& \& T{
1484 Turn off error logging through syslog(3). (default)
1486 set properties \& \& T{
1487 String value that is ignored by fetchmail (may be used by extension
1492 Here are the legal server options:
1496 Keyword Opt Mode Function
1499 Specify DNS name of mailserver, overriding poll name
1501 proto[col] \-p \& T{
1502 Specify protocol (case insensitive):
1503 POP2, POP3, IMAP, APOP, KPOP
1505 local[domains] \& m T{
1506 Specify domain(s) to be regarded as local
1509 Specify TCP/IP service port (obsolete, use 'service' instead).
1512 Specify service name (a numeric value is also allowed and
1513 considered a TCP/IP port number).
1515 auth[enticate] \& \& T{
1516 Set authentication type (default 'any')
1519 Server inactivity timeout in seconds (default 300)
1522 Specify envelope-address header name
1525 Disable looking for envelope address
1528 Qmail virtual domain prefix to remove from user name
1531 Specify alternate DNS names of mailserver
1534 specify IP interface(s) that must be up for server poll to take place
1537 Specify IP address to monitor for activity
1540 Specify command through which to make server connections.
1543 Specify command through which to make listener connections.
1546 Enable DNS lookup for multidrop (default)
1549 Disable DNS lookup for multidrop
1552 Do comparison by IP address for multidrop
1554 no checkalias \& m T{
1555 Do comparison by name for multidrop (default)
1558 Force POP3 to use client-side UIDLs (recommended)
1561 Turn off POP3 use of client-side UIDLs (default)
1564 Only check this site every N poll cycles; N is a numeric argument.
1567 Add poll tracing information to the Received header
1570 Set Kerberos principal (only useful with imap and kerberos)
1573 Set name for RFC2554 authentication to the ESMTP server.
1575 esmtppassword \& \& T{
1576 Set password for RFC2554 authentication to the ESMTP server.
1580 Here are the legal user options:
1584 Keyword Opt Mode Function
1586 user[name] \-u \& T{
1587 Set remote user name
1588 (local user name if name followed by 'here')
1591 Connect local and remote user names
1594 Connect local and remote user names
1597 Specify remote account password
1600 Connect to server over the specified base protocol using SSL encryption
1603 Specify file for client side public SSL certificate
1606 Specify file for client side private SSL key
1609 Force ssl protocol for connection
1612 Specify remote folder to query
1615 Specify smtp host(s) to forward to
1617 fetchdomains \& m T{
1618 Specify domains for which mail should be fetched
1620 smtpaddress \-D \& T{
1621 Specify the domain to be put in RCPT TO lines
1624 Specify the user and domain to be put in RCPT TO lines
1627 Specify what SMTP returns are interpreted as spam-policy blocks
1630 Specify MDA for local delivery
1633 Specify BSMTP batch file to append to
1636 Command to be executed before each connection
1638 postconnect \& \& T{
1639 Command to be executed after each connection
1642 Don't delete seen messages from server
1645 Flush all seen messages before querying (DANGEROUS)
1648 Flush all oversized messages before querying
1651 Fetch all messages whether seen or not
1654 Rewrite destination addresses for reply (default)
1657 Strip carriage returns from ends of lines
1660 Force carriage returns at ends of lines
1663 Force BODY=8BITMIME to ESMTP listener
1666 Strip Status and X-Mozilla-Status lines out of incoming mail
1668 dropdelivered \& \& T{
1669 Strip Delivered-To lines out of incoming mail
1672 Convert quoted-printable to 8-bit in MIME messages
1675 Idle waiting for new messages after each poll (IMAP only)
1678 Delete seen messages from server (default)
1681 Don't flush all seen messages before querying (default)
1683 no fetchall \& \& T{
1684 Retrieve only new messages (default)
1687 Don't rewrite headers
1690 Don't strip carriage returns (default)
1693 Don't force carriage returns at EOL (default)
1695 no pass8bits \& \& T{
1696 Don't force BODY=8BITMIME to ESMTP listener (default)
1698 no dropstatus \& \& T{
1699 Don't drop Status headers (default)
1701 no dropdelivered \& \& T{
1702 Don't drop Delivered\-To headers (default)
1704 no mimedecode \& \& T{
1705 Don't convert quoted-printable to 8-bit in MIME messages (default)
1708 Don't idle waiting for new messages after each poll (IMAP only)
1711 Set message size limit
1714 Set message size warning interval
1716 batchlimit \-b \& T{
1717 Max # messages to forward in single connect
1719 fetchlimit \-B \& T{
1720 Max # messages to fetch in single connect
1722 fetchsizelimit \& \& T{
1723 Max # message sizes to fetch in single transaction
1726 Use binary search for first unseen message (POP3 only)
1729 Perform an expunge on every #th message (IMAP and POP3 only)
1732 String value is ignored by fetchmail (may be used by extension scripts)
1736 Remember that all user options must \fIfollow\fR all server options.
1738 In the .fetchmailrc file, the 'envelope' string argument may be
1739 preceded by a whitespace-separated number. This number, if specified,
1740 is the number of such headers to skip over (that is, an argument of 1
1741 selects the second header of the given type). This is sometime useful
1742 for ignoring bogus envelope headers created by an ISP's local delivery
1743 agent or internal forwards (through mail inspection systems, for
1745 .SS Keywords Not Corresponding To Option Switches
1747 The 'folder' and 'smtphost' options (unlike their command-line
1748 equivalents) can take a space- or comma-separated list of names
1751 All options correspond to the obvious command-line arguments, except
1752 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1753 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1754 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1755 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1756 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'no idle',
1759 The 'via' option is for if you want to have more
1760 than one configuration pointing at the same site. If it is present,
1761 the string argument will be taken as the actual DNS name of the
1762 mailserver host to query.
1763 This will override the argument of poll, which can then simply be a
1764 distinct label for the configuration (e.g. what you would give on the
1765 command line to explicitly query this host).
1767 The 'interval' option (which takes a numeric argument) allows you to poll a
1768 server less frequently than the basic poll interval. If you say
1769 \&'interval N' the server this option is attached to will only be
1770 queried every N poll intervals.
1772 The 'is' or 'to' keywords associate the following local (client)
1773 name(s) (or server-name to client-name mappings separated by =) with
1774 the mailserver user name in the entry. If an is/to list has '*' as
1775 its last name, unrecognized names are simply passed through.
1777 A single local name can be used to support redirecting your mail when
1778 your username on the client machine is different from your name on the
1779 mailserver. When there is only a single local name, mail is forwarded
1780 to that local username regardless of the message's Received, To, Cc,
1781 and Bcc headers. In this case
1783 never does DNS lookups.
1785 When there is more than one local name (or name mapping) the
1786 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1787 headers of retrieved mail (this is 'multidrop mode'). It looks for
1788 addresses with hostname parts that match your poll name or your 'via',
1789 \&'aka' or 'localdomains' options, and usually also for hostname parts
1790 which DNS tells it are aliases of the mailserver. See the discussion
1791 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1792 matching addresses are handled.
1794 If \fIfetchmail\fR cannot match any mailserver usernames or
1795 localdomain addresses, the mail will be bounced.
1796 Normally it will be bounced to the sender, but if the 'bouncemail'
1797 global option is off, the mail will go to the local postmaster instead.
1798 (see the 'postmaster' global option). See also BUGS.
1800 The 'dns' option (normally on) controls the way addresses from
1801 multidrop mailboxes are checked. On, it enables logic to check each
1802 host address that does not match an 'aka' or 'localdomains' declaration
1803 by looking it up with DNS. When a mailserver username is recognized
1804 attached to a matching hostname part, its local mapping is added to
1805 the list of local recipients.
1807 The 'checkalias' option (normally off) extends the lookups performed
1808 by the 'dns' keyword in multidrop mode, providing a way to cope with
1809 remote MTAs that identify themselves using their canonical name, while
1810 they're polled using an alias.
1811 When such a server is polled, checks to extract the envelope address
1814 reverts to delivery using the To/Cc/Bcc headers (See below
1815 \&'Header vs. Envelope addresses').
1816 Specifying this option instructs
1818 to retrieve all the IP addresses associated with both the poll name
1819 and the name used by the remote MTA and to do a comparison of the IP
1820 addresses. This comes in handy in situations where the remote server
1821 undergoes frequent canonical name changes, that would otherwise
1822 require modifications to the rcfile. 'checkalias' has no effect if
1823 \&'no dns' is specified in the rcfile.
1825 The 'aka' option is for use with multidrop mailboxes. It allows you
1826 to pre-declare a list of DNS aliases for a server. This is an
1827 optimization hack that allows you to trade space for speed. When
1829 while processing a multidrop mailbox, grovels through message headers
1830 looking for names of the mailserver, pre-declaring common ones can
1831 save it from having to do DNS lookups. Note: the names you give
1832 as arguments to 'aka' are matched as suffixes -- if you specify
1833 (say) 'aka netaxs.com', this will match not just a hostname
1834 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1835 (say) pop3.netaxs.com and mail.netaxs.com.
1837 The 'localdomains' option allows you to declare a list of domains
1838 which fetchmail should consider local. When fetchmail is parsing
1839 address lines in multidrop modes, and a trailing segment of a host
1840 name matches a declared local domain, that address is passed through
1841 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1844 If you are using 'localdomains', you may also need to specify 'no
1845 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1846 an envelope address from the Received line or X-Envelope-To header or
1847 whatever header has been previously set by 'envelope'. If you set 'no
1848 envelope' in the defaults entry it is possible to undo that in
1849 individual entries by using 'envelope <string>'. As a special case,
1850 \&'envelope "Received"' restores the default parsing of
1853 The \fBpassword\fR option requires a string argument, which is the password
1854 to be used with the entry's server.
1856 The 'preconnect' keyword allows you to specify a shell command to be
1857 executed just before each time
1859 establishes a mailserver connection. This may be useful if you are
1860 attempting to set up secure POP connections with the aid of
1862 If the command returns a nonzero status, the poll of that mailserver
1865 Similarly, the 'postconnect' keyword similarly allows you to specify a
1866 shell command to be executed just after each time a mailserver
1867 connection is taken down.
1869 The 'forcecr' option controls whether lines terminated by LF only are
1870 given CRLF termination before forwarding. Strictly speaking RFC821
1871 requires this, but few MTAs enforce the requirement it so this option
1872 is normally off (only one such MTA, qmail, is in significant use at
1875 The 'stripcr' option controls whether carriage returns are stripped
1876 out of retrieved mail before it is forwarded. It is normally not
1877 necessary to set this, because it defaults to 'on' (CR stripping
1878 enabled) when there is an MDA declared but 'off' (CR stripping
1879 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1880 both on, 'stripcr' will override.
1882 The 'pass8bits' option exists to cope with Microsoft mail programs that
1883 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1884 this option off (the default) and such a header present,
1886 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1887 messages actually using 8-bit ISO or KOI-8 character sets, which will
1888 be garbled by having the high bits of all characters stripped. If
1889 \&'pass8bits' is on,
1891 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1892 the listener is 8-bit-clean (as all the major ones now are) the right
1893 thing will probably result.
1895 The 'dropstatus' option controls whether nonempty Status and
1896 X-Mozilla-Status lines are retained in fetched mail (the default) or
1897 discarded. Retaining them allows your MUA to see what messages (if
1898 any) were marked seen on the server. On the other hand, it can
1899 confuse some new-mail notifiers, which assume that anything with a
1900 Status line in it has been seen. (Note: the empty Status lines
1901 inserted by some buggy POP servers are unconditionally discarded.)
1903 The 'dropdelivered' option controls whether Delivered\-To headers will
1904 be kept in fetched mail (the default) or discarded. These headers are
1905 added by Qmail and Postfix mailservers in order to avoid mail loops but
1906 may get in your way if you try to "mirror" a mailserver within the same
1907 domain. Use with caution.
1909 The 'mimedecode' option controls whether MIME messages using the
1910 quoted-printable encoding are automatically converted into pure 8-bit
1911 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1912 listener (that includes all of the major MTAs like sendmail), then
1913 this will automatically convert quoted-printable message headers and
1914 data into 8-bit data, making it easier to understand when reading
1915 mail. If your e-mail programs know how to deal with MIME messages,
1916 then this option is not needed. The mimedecode option is off by
1917 default, because doing RFC2047 conversion on headers throws away
1918 character-set information and can lead to bad results if the encoding
1919 of the headers differs from the body encoding.
1921 The 'idle' option is intended to be used with IMAP servers supporting
1922 the RFC2177 IDLE command extension, but does not strictly require it.
1923 If it is enabled, and fetchmail detects that IDLE is supported, an
1924 IDLE will be issued at the end of each poll. This will tell the IMAP
1925 server to hold the connection open and notify the client when new mail
1926 is available. If IDLE is not supported, fetchmail will simulate it by
1927 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1928 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1929 sequences. On the other hand, an IDLE connection will eat almost all
1930 of your fetchmail's time, because it will never drop the connection
1931 and allow other polls to occur unless the server times out the IDLE.
1932 It also doesn't work with multiple folders; only the first folder will
1936 The 'properties' option is an extension mechanism. It takes a string
1937 argument, which is ignored by fetchmail itself. The string argument may be
1938 used to store configuration information for scripts which require it.
1939 In particular, the output of '\-\-configdump' option will make properties
1940 associated with a user entry readily available to a Python script.
1942 .SS Miscellaneous Run Control Options
1943 The words 'here' and 'there' have useful English-like
1944 significance. Normally 'user eric is esr' would mean that
1945 mail for the remote user 'eric' is to be delivered to 'esr',
1946 but you can make this clearer by saying 'user eric there is esr here',
1947 or reverse it by saying 'user esr here is eric there'
1949 Legal protocol identifiers for use with the 'protocol' keyword are:
1952 auto (or AUTO) (legacy, to be removed from future release)
1953 pop2 (or POP2) (legacy, to be removed from future release)
1962 Legal authentication types are 'any', 'password', 'kerberos',
1963 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram\-md5', 'otp', 'msn'
1964 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1965 authentication by normal transmission of a password (the password may be
1966 plain text or subject to protocol-specific encryption as in APOP);
1967 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1968 start of each query instead, and send an arbitrary string as the
1969 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1970 See the description of the 'auth' keyword for more.
1972 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1973 authentication. These defaults may be overridden by later options.
1975 There are some global option statements: 'set logfile'
1976 followed by a string sets the same global specified by \-\-logfile. A
1977 command-line \-\-logfile option will override this. Note that \-\-logfile is
1978 only effective if fetchmail detaches itself from the terminal. Also,
1979 \&'set daemon' sets the poll interval as \-\-daemon does. This can be
1980 overridden by a command-line \-\-daemon option; in particular \-\-daemon\~0
1981 can be used to force foreground operation. The 'set postmaster'
1982 statement sets the address to which multidrop mail defaults if there are
1983 no local matches. Finally, 'set syslog' sends log messages to
1986 .SH DEBUGGING FETCHMAIL
1987 .SS Fetchmail crashing
1988 There are various ways in that fetchmail may "crash", i. e. stop
1989 operation suddenly and unexpectedly. A "crash" usually refers to an
1990 error condition that the software did not handle by itself. A well-known
1991 failure mode is the "segmentation fault" or "signal 11" or "SIGSEGV" or
1992 just "segfault" for short. These can be caused by hardware or by software
1993 problems. Software-induced segfaults can usually be reproduced easily
1994 and in the same place, whereas hardware-induced segfaults can go away if
1995 the computer is rebooted, or powered off for a few hours, and can happen
1996 in random locations even if you use the software the same way.
1998 For solving hardware-induced segfaults, find the faulty component and repair or
1999 replace it. <http://www.bitwizard.nl/sig11/> may help you with details.
2001 For solving software-induced segfaults, the developers may need a "stack
2004 .SS Enabling fetchmail core dumps
2005 By default, fetchmail suppresses core dumps as these might contain
2006 passwords and other sensitive information. For debugging fetchmail
2007 crashes, obtaining a "stack backtrace" from a core dump is often the
2008 quickest way to solve the problem, and when posting your problem on a
2009 mailing list, the developers may ask you for a "backtrace".
2011 1. To get useful backtraces, fetchmail needs to be installed without
2012 getting stripped of its compilation symbols. Unfortunately, most
2013 binary packages that are installed are stripped, and core files from
2014 symbol-stripped programs are worthless. So you may need to recompile
2015 fetchmail. On many systems, you can type
2018 file `which fetchmail`
2021 to find out if fetchmail was symbol-stripped or not. If yours was
2022 unstripped, fine, proceed, if it was stripped, you need to recompile the
2023 source code first. You do not usually need to install fetchmail in order
2026 2. The shell environment that starts fetchmail needs to enable core
2027 dumps. The key is the "maximum core (file) size" that can usually be
2028 configured with a tool named "limit" or "ulimit". See the documentation
2029 for your shell for details. In the popular bash shell, "ulimit \-Sc
2030 unlimited" will allow the core dump.
2032 3. You need to tell fetchmail, too, to allow core dumps. To do
2033 this, run fetchmail with the \fB\-d0 \-v\fP options. It is often easier
2034 to also add \fB\-\-nosyslog \-N\fR as well.
2036 Finally, you need to reproduce the crash. You can just start fetchmail
2037 from the directory where you compiled it by typing \fB./fetchmail\fR,
2038 so the complete command line will start with \fB./fetchmail \-Nvd0
2039 \&\-\-nosyslog\fR and perhaps list your other options.
2041 After the crash, run your debugger to obtain the core dump. The
2042 debugger will often be GNU GDB, you can then type (adjust paths as
2043 necessary) \fBgdb ./fetchmail fetchmail.core\fR and then, after GDB
2044 has started up and read all its files, type \fBbacktrace full\fR, save
2045 the output (copy & paste will do, the backtrace will be read by a human)
2046 and then type \fBquit\fR to leave gdb.
2048 on some systems, the core
2049 files have different names, they might contain a number instead of the
2050 program name, or number and name, but it will usually have "core" as
2053 .SH INTERACTION WITH RFC 822
2054 When trying to determine the originating address of a message,
2055 fetchmail looks through headers in the following order:
2059 Resent-Sender: (ignored if it doesn't contain an @ or !)
2060 Sender: (ignored if it doesn't contain an @ or !)
2067 The originating address is used for logging, and to set the MAIL FROM
2068 address when forwarding to SMTP. This order is intended to cope
2069 gracefully with receiving mailing list messages in multidrop mode. The
2070 intent is that if a local address doesn't exist, the bounce message
2071 won't be returned blindly to the author or to the list itself, but
2072 rather to the list manager (which is less annoying).
2074 In multidrop mode, destination headers are processed as follows:
2075 First, fetchmail looks for the Received: header (or whichever one is
2076 specified by the 'envelope' option) to determine the local
2077 recipient address. If the mail is addressed to more than one recipient,
2078 the Received line won't contain any information regarding recipient addresses.
2080 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
2081 lines. If they exist, they should contain the final recipients and
2082 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent\-*
2083 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
2084 looked for. (The presence of a Resent\-To: is taken to imply that the
2085 person referred by the To: address has already received the original
2088 .SH CONFIGURATION EXAMPLES
2089 Note that although there are password declarations in a good many
2090 of the examples below, this is mainly for illustrative purposes.
2091 We recommend stashing account/password pairs in your $HOME/.netrc
2092 file, where they can be used not just by fetchmail but by ftp(1) and
2098 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
2104 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
2107 Or, using some abbreviations:
2110 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
2113 Multiple servers may be listed:
2116 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
2117 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
2120 Here's a version of those two with more whitespace and some noise words:
2123 poll pop.provider.net proto pop3
2124 user "jsmith", with password secret1, is "jsmith" here;
2125 poll other.provider.net proto pop2:
2126 user "John.Smith", with password "My^Hat", is "John.Smith" here;
2129 This version is much easier to read and doesn't cost significantly
2130 more (parsing is done only once, at startup time).
2133 If you need to include whitespace in a parameter string, enclose the
2134 string in double quotes. Thus:
2137 poll mail.provider.net with proto pop3:
2138 user "jsmith" there has password "u can't krak this"
2139 is jws here and wants mda "/bin/mail"
2142 You may have an initial server description headed by the keyword
2143 \&'defaults' instead of 'poll' followed by a name. Such a record
2144 is interpreted as defaults for all queries to use. It may be overwritten
2145 by individual server descriptions. So, you could write:
2150 poll pop.provider.net
2152 poll mail.provider.net
2153 user "jjsmith" there has password "secret2"
2156 It's possible to specify more than one user per server (this is only
2157 likely to be useful when running fetchmail in daemon mode as root).
2158 The 'user' keyword leads off a user description, and every user specification
2159 in a multi-user entry must include it. Here's an example:
2162 poll pop.provider.net proto pop3 port 3111
2163 user "jsmith" with pass "secret1" is "smith" here
2164 user jones with pass "secret2" is "jjones" here keep
2167 This associates the local username 'smith' with the pop.provider.net
2168 username 'jsmith' and the local username 'jjones' with the
2169 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2170 server after download.
2172 Here's what a simple retrieval configuration for a multi-drop mailbox
2176 poll pop.provider.net:
2177 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2180 This says that the mailbox of account 'maildrop' on the server is a
2181 multi-drop box, and that messages in it should be parsed for the
2182 server user names 'golux', 'hurkle', and 'snark'. It further
2183 specifies that 'golux' and 'snark' have the same name on the
2184 client as on the server, but mail for server user 'hurkle' should be
2185 delivered to client user 'happy'.
2187 Here's an example of another kind of multidrop connection:
2190 poll pop.provider.net localdomains loonytoons.org toons.org:
2191 user maildrop with pass secret1 to * here
2194 This also says that the mailbox of account 'maildrop' on the server is
2195 a multi-drop box. It tells fetchmail that any address in the
2196 loonytoons.org or toons.org domains (including sub-domain addresses like
2197 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2198 listener without modification. Be careful of mail loops if you do this!
2200 Here's an example configuration using ssh and the plugin option. The
2201 queries are made directly on the stdin and stdout of imapd via ssh.
2202 Note that in this setup, IMAP authentication can be skipped.
2205 poll mailhost.net with proto imap:
2206 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2207 user esr is esr here
2210 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2211 Use the multiple-local-recipients feature with caution -- it can bite.
2212 All multidrop features are ineffective in ETRN and ODMR modes.
2214 Also, note that in multidrop mode duplicate mails are suppressed. A
2215 piece of mail is considered duplicate if it has the same message-ID as
2216 the message immediately preceding and more than one addressee. Such
2217 runs of messages may be generated when copies of a message addressed
2218 to multiple users are delivered to a multidrop box.
2220 .SS Header vs. Envelope addresses
2221 The fundamental problem is that by having your mailserver toss several
2222 peoples' mail in a single maildrop box, you may have thrown away
2223 potentially vital information about who each piece of mail was
2224 actually addressed to (the 'envelope address', as opposed to the
2225 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2226 at the receiving end). This 'envelope address' is the address you need
2227 in order to reroute mail properly.
2231 can deduce the envelope address. If the mailserver MTA is
2233 and the item of mail had just one recipient, the MTA will have written
2234 a 'by/for' clause that gives the envelope addressee into its Received
2235 header. But this doesn't work reliably for other MTAs, nor if there is
2236 more than one recipient. By default, \fIfetchmail\fR looks for
2237 envelope addresses in these lines; you can restore this default with
2238 \&\-E "Received" or 'envelope Received'.
2240 .B As a better alternative,
2241 some SMTP listeners and/or mail servers insert a header
2242 in each message containing a copy of the envelope addresses. This
2243 header (when it exists) is often 'X\-Original\-To', 'Delivered\-To' or
2244 \&'X\-Envelope\-To'. Fetchmail's assumption about this can be changed with
2245 the \-E or 'envelope' option. Note that writing an envelope header of
2246 this kind exposes the names of recipients (including blind-copy
2247 recipients) to all receivers of the messages, so the upstream must store
2248 one copy of the message per recipient to avoid becoming a privacy problem.
2250 Postfix, since version 2.0, writes an X\-Original\-To: header which
2251 contains a copy of the envelope as it was received.
2253 Qmail and Postfix generally write a 'Delivered\-To' header upon
2254 delivering the message to the mail spool and use it to avoid mail loops.
2255 Qmail virtual domains however will prefix the user name with a string
2256 that normally matches the user's domain. To remove this prefix you can
2257 use the \-Q or 'qvirtual' option.
2259 Sometimes, unfortunately, neither of these methods works. That is the
2260 point when you should contact your ISP and ask them to provide such an
2261 envelope header, and you should not use multidrop in this situation.
2262 When they all fail, fetchmail must fall back on the contents of To/Cc
2263 headers (Bcc headers are not available - see below) to try to determine
2264 recipient addressees -- and these are unreliable.
2265 In particular, mailing-list software often ships mail with only
2266 the list broadcast address in the To header.
2268 .B Note that a future version of fetchmail may remove To/Cc parsing!
2272 cannot deduce a recipient address that is local, and the intended
2273 recipient address was anyone other than fetchmail's invoking user,
2274 .B mail will get lost.
2275 This is what makes the multidrop feature risky without proper envelope
2278 A related problem is that when you blind-copy a mail message, the Bcc
2279 information is carried \fIonly\fR as envelope address (it's removed from
2280 the headers by the sending mail server, so fetchmail can see it only if
2281 there is an X-\Envelope\-To header). Thus, blind-copying to someone who
2282 gets mail over a fetchmail multidrop link will fail unless the the
2283 mailserver host routinely writes X\-Envelope\-To or an equivalent header
2284 into messages in your maildrop.
2286 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2287 server you're fetching from (1) stores one copy of the message per
2288 recipient in \fBIyour\fP domain and (2) records the envelope
2289 information in a special header (X\-Original\-To, Delivered\-To,
2290 X\-Envelope\-To).\fR
2292 .SS Good Ways To Use Multidrop Mailboxes
2293 Multiple local names can be used to administer a mailing list from the
2294 client side of a \fIfetchmail\fR collection. Suppose your name is
2295 \&'esr', and you want to both pick up your own mail and maintain a mailing
2296 list called (say) "fetchmail-friends", and you want to keep the alias
2297 list on your client machine.
2299 On your server, you can alias 'fetchmail\-friends' to 'esr'; then, in
2300 your \fI.fetchmailrc\fR, declare 'to esr fetchmail\-friends here'.
2301 Then, when mail including 'fetchmail\-friends' as a local address
2302 gets fetched, the list name will be appended to the list of
2303 recipients your SMTP listener sees. Therefore it will undergo alias
2304 expansion locally. Be sure to include 'esr' in the local alias
2305 expansion of fetchmail\-friends, or you'll never see mail sent only to
2306 the list. Also be sure that your listener has the "me-too" option set
2307 (sendmail's \-oXm command-line option or OXm declaration) so your name
2308 isn't removed from alias expansions in messages you send.
2310 This trick is not without its problems, however. You'll begin to see
2311 this when a message comes in that is addressed only to a mailing list
2312 you do \fInot\fR have declared as a local name. Each such message
2313 will feature an 'X\-Fetchmail\-Warning' header which is generated
2314 because fetchmail cannot find a valid local name in the recipient
2315 addresses. Such messages default (as was described above) to being
2316 sent to the local user running
2318 but the program has no way to know that that's actually the right thing.
2320 .SS Bad Ways To Abuse Multidrop Mailboxes
2321 Multidrop mailboxes and
2323 serving multiple users in daemon mode do not mix. The problem, again, is
2324 mail from mailing lists, which typically does not have an individual
2325 recipient address on it. Unless
2327 can deduce an envelope address, such mail will only go to the account
2328 running fetchmail (probably root). Also, blind-copied users are very
2329 likely never to see their mail at all.
2331 If you're tempted to use
2333 to retrieve mail for multiple users from a single mail drop via POP or
2334 IMAP, think again (and reread the section on header and envelope
2335 addresses above). It would be smarter to just let the mail sit in the
2336 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2337 SMTP sends periodically (of course, this means you have to poll more
2338 frequently than the mailserver's expiry period). If you can't arrange
2339 this, try setting up a UUCP feed.
2341 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2342 your mailserver writes an envelope-address header that fetchmail can
2343 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2346 .SS Speeding Up Multidrop Checking
2347 Normally, when multiple users are declared
2349 extracts recipient addresses as described above and checks each host
2350 part with DNS to see if it's an alias of the mailserver. If so, the
2351 name mappings described in the "to ... here" declaration are done and
2352 the mail locally delivered.
2354 This is a convenient but also slow method. To speed
2355 it up, pre-declare mailserver aliases with 'aka'; these are checked
2356 before DNS lookups are done. If you're certain your aka list contains
2358 DNS aliases of the mailserver (and all MX names pointing at it - note
2359 this may change in a future version)
2360 you can declare 'no dns' to suppress DNS lookups entirely and
2361 \fIonly\fR match against the aka list.
2364 To facilitate the use of
2366 in shell scripts, an exit code is returned to give an indication
2367 of what occurred during a given connection.
2369 The exit codes returned by
2373 One or more messages were successfully retrieved (or, if the \-c option
2374 was selected, were found waiting but not retrieved).
2376 There was no mail awaiting retrieval. (There may have been old mail still
2377 on the server but not selected for retrieval.)
2379 An error was encountered when attempting to open a socket to retrieve
2380 mail. If you don't know what a socket is, don't worry about it --
2381 just treat this as an 'unrecoverable error'. This error can also be
2382 because a protocol fetchmail wants to use is not listed in /etc/services.
2384 The user authentication step failed. This usually means that a bad
2385 user-id, password, or APOP id was specified. Or it may mean that you
2386 tried to run fetchmail under circumstances where it did not have
2387 standard input attached to a terminal and could not prompt for a
2390 Some sort of fatal protocol error was detected.
2392 There was a syntax error in the arguments to
2395 The run control file had bad permissions.
2397 There was an error condition reported by the server. Can also
2400 timed out while waiting for the server.
2402 Client-side exclusion error. This means
2404 either found another copy of itself already running, or failed in such
2405 a way that it isn't sure whether another copy is running.
2407 The user authentication step failed because the server responded "lock
2408 busy". Try again after a brief pause! This error is not implemented
2409 for all protocols, nor for all servers. If not implemented for your
2410 server, "3" will be returned instead, see above. May be returned when
2411 talking to qpopper or other servers that can respond with "lock busy"
2412 or some similar text containing the word "lock".
2416 run failed while trying to do an SMTP port open or transaction.
2418 Fatal DNS error. Fetchmail encountered an error while performing
2419 a DNS lookup at startup and could not proceed.
2421 BSMTP batch file could not be opened.
2423 Poll terminated by a fetch limit (see the \-\-fetchlimit option).
2425 Server busy indication.
2427 Server timed out during an IMAP IDLE.
2429 Internal error. You should see a message on standard error with
2434 queries more than one host, return status is 0 if \fIany\fR query
2435 successfully retrieved mail. Otherwise the returned error status is
2436 that of the last host queried.
2441 default run control file
2444 default location of file associating hosts with last message IDs seen
2445 (used only with newer RFC1939-compliant POP3 servers supporting the
2449 lock file to help prevent concurrent runs (non-root mode).
2452 your FTP run control file, which (if present) will be searched for
2453 passwords as a last resort before prompting for one interactively.
2455 /var/run/fetchmail.pid
2456 lock file to help prevent concurrent runs (root mode, Linux systems).
2459 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2462 If the FETCHMAILUSER variable is set, it is used as the name of the
2463 calling user (default local name) for purposes such as mailing error
2464 notifications. Otherwise, if either the LOGNAME or USER variable is
2465 correctly set (e.g. the corresponding UID matches the session user ID)
2466 then that name is used as the default local name. Otherwise
2467 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2468 session ID (this elaborate logic is designed to handle the case of
2469 multiple names per userid gracefully).
2471 If the environment variable FETCHMAILHOME is set to a valid and
2472 existing directory name, fetchmail will read $FETCHMAILHOME/fetchmailrc
2473 (the dot is missing in this case), $FETCHMAILHOME/.fetchids and
2474 $FETCHMAILHOME/.fetchmail.pid rather than from the user's home
2475 directory. The .netrc file is always looked for in the the invoking
2476 user's home directory regardless of FETCHMAILHOME's setting.
2478 If the HOME_ETC variable is set, fetchmail will read
2479 $HOME_ETC/.fetchmailrc instead of ~/.fetchmailrc.
2481 If HOME_ETC and FETCHMAILHOME are set, HOME_ETC will be ignored.
2486 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2487 forces a poll of all non-skipped servers (this is in accordance with
2488 the usual conventions for system daemons).
2492 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2493 so SIGHUP due to logout can retain the default action of killing it).
2497 in foreground while a background fetchmail is running will do
2498 whichever of these is appropriate to wake it up.
2500 .SH BUGS AND KNOWN PROBLEMS
2502 The assumptions that the DNS and in particular the checkalias options
2503 make are not often sustainable. For instance, it has become uncommon for
2504 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2505 MX lookups may go away in a future release.
2507 The mda and plugin options interact badly. In order to collect error
2508 status from the MDA, fetchmail has to change its normal signal
2509 handling so that dead plugin processes don't get reaped until the end
2510 of the poll cycle. This can cause resource starvation if too many
2511 zombies accumulate. So either don't deliver to a MDA using plugins or
2512 risk being overrun by an army of undead.
2514 The \-\-interface option does not support IPv6 and it is doubtful if it
2515 ever will, since there is no portable way to query interface IPv6
2518 The RFC822 address parser used in multidrop mode chokes on some
2519 @-addresses that are technically legal but bizarre. Strange uses of
2520 quoting and embedded comments are likely to confuse it.
2522 In a message with multiple envelope headers, only the last one
2523 processed will be visible to fetchmail.
2525 Use of some of these protocols requires that the program send
2526 unencrypted passwords over the TCP/IP connection to the mailserver.
2527 This creates a risk that name/password pairs might be snaffled with a
2528 packet sniffer or more sophisticated monitoring software. Under Linux
2529 and FreeBSD, the \-\-interface option can be used to restrict polling to
2530 availability of a specific interface device with a specific local or
2531 remote IP address, but snooping is still possible if (a) either host
2532 has a network device that can be opened in promiscuous mode, or (b)
2533 the intervening network link can be tapped. We recommend the use of
2535 tunnelling to not only shroud your passwords but encrypt the entire
2538 Use of the %F or %T escapes in an mda option could open a security
2539 hole, because they pass text manipulable by an attacker to a shell
2540 command. Potential shell characters are replaced by '_' before
2541 execution. The hole is further reduced by the fact that fetchmail
2542 temporarily discards any suid privileges it may have while running the
2543 MDA. For maximum safety, however, don't use an mda command containing
2544 %F or %T when fetchmail is run from the root account itself.
2546 Fetchmail's method of sending bounces due to errors or spam-blocking and
2547 spam bounces requires that port 25 of localhost be available for sending
2552 while a background instance is running and break the syntax, the
2553 background instance will die silently. Unfortunately, it can't
2554 die noisily because we don't yet know whether syslog should be enabled.
2555 On some systems, fetchmail dies quietly even if there is no syntax
2556 error; this seems to have something to do with buggy terminal ioctl
2559 The \-f\~\- option (reading a configuration from stdin) is incompatible
2560 with the plugin option.
2562 The 'principal' option only handles Kerberos IV, not V.
2564 Interactively entered passwords are truncated after 63 characters. If
2565 you really need to use a longer password, you will have to use a
2568 A backslash as the last character of a configuration file will be
2569 flagged as a syntax error rather than ignored.
2571 Send comments, bug reports, gripes, and the like to the
2572 fetchmail\-devel list <fetchmail\-devel@lists.berlios.de>. An HTML FAQ is
2573 available at the fetchmail home page; surf to
2574 http://fetchmail.berlios.de/ or do a WWW search for pages with
2575 \&'fetchmail' in their titles.
2578 Fetchmail is currently maintained by Matthias Andree and Rob Funk with
2579 major assistance from Sunil Shetye (for code) and Rob MacGregor (for the
2582 Most of the code is from Eric S. Raymond <esr@snark.thyrsus.com>. Too
2583 many other people to name here have contributed code and patches.
2585 This program is descended from and replaces
2587 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2588 but some of its interface design is directly traceable to that
2591 This manual page has been improved by R.\ Hannes Beinert and H\['e]ctor
2595 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2597 The fetchmail home page: <http://fetchmail.berlios.de/>
2599 The maildrop home page: <http://www.courier-mta.org/maildrop/>
2600 .SH APPLICABLE STANDARDS
2602 Note that this list is just a collection of references and not a
2603 statement as to the actual protocol conformance or requirements in
2607 RFC 821, RFC 2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2611 RFC 822, RFC 2822, RFC 1123, RFC 1892, RFC 1894.
2617 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC 1734, RFC 1939, RFC 1957,
2621 RFC 1460, RFC 1725, RFC 1939.
2630 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
projects / ~andy / fetchmail / blob