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.
10 fetchmail \- fetch mail from a POP, IMAP, ETRN, or ODMR-capable server
13 \fBfetchmail\fR [\fIoption...\fR] [\fImailserver...\fR]
19 is a mail-retrieval and forwarding utility; it fetches mail from
20 remote mailservers and forwards it to your local (client) machine's
21 delivery system. You can then handle the retrieved mail using normal
22 mail user agents such as \fImutt\fR(1), \fIelm\fR(1) or \fIMail\fR(1).
23 The \fIfetchmail\fR utility can be run in a daemon mode to repeatedly
24 poll one or more systems at a specified interval.
28 program can gather mail from servers supporting any of the common
29 mail-retrieval protocols: POP2 (legacy, to be removed from future
30 release), POP3, IMAP2bis, IMAP4, and IMAP4rev1.
31 It can also use the ESMTP ETRN extension and ODMR. (The RFCs describing all
32 these protocols are listed at the end of this manual page.)
36 is primarily intended to be used over on-demand TCP/IP links (such as
37 SLIP or PPP connections), it may also be useful as a message transfer
38 agent for sites which refuse for security reasons to permit
39 (sender-initiated) SMTP transactions with sendmail.
43 is used with a POP or an IMAP server, it has two fundamental modes of
44 operation for each user account from which it retrieves mail:
45 \fIsingledrop\fR- and \fImultidrop\fR-mode. In singledrop-mode,
47 assumes that all messages in the user's account are intended for a single
48 recipient. An individual mail message will not be inspected for recipient
49 information, rather, the identity of the recipient will either default to
50 the local user currently executing \fIfetchmail\fR,
51 or else will need to be explicitly specified in the configuration file.
52 Singledrop-mode is used when the fetchmailrc configuration contains at
53 most a single local user specification for a given server account.
57 is not able to assume that there is only a single recipient, but rather
58 that the mail server account actually contains mail intended for any
59 number of different recipients. Therefore,
61 must attempt to deduce the proper "envelope recipient" from the mail
62 headers of each message. In this mode of operation
64 almost resembles an MTA, however it is important to note that neither
65 the POP nor IMAP protocols were intended for use in this fashion, and
66 hence envelope information is not directly available. Instead,
68 must resort to a process of informed guess-work in an attempt to
69 discover the true envelope recipient of a message. Even if this
70 information is present in the headers, the process can
71 be error-prone and is dependent upon the specific mail server used
72 for mail retrieval. Multidrop-mode is used when more than one local
73 user is specified for a particular server account in the configuration
74 file. Note that the forgoing discussion of singledrop- and
75 multidrop-modes does not apply to the ESMTP ETRN or ODMR retrieval
76 methods, since they are based upon the SMTP protocol which
77 specifically provides the envelope recipient to \fIfetchmail\fR.
79 As each message is retrieved \fIfetchmail\fR normally delivers it via SMTP to
80 port 25 on the machine it is running on (localhost), just as though it
81 were being passed in over a normal TCP/IP link. \fIfetchmail\fR provides
82 the SMTP server with an envelope recipient derived in the manner described
83 previously. The mail will then be
84 delivered locally via your system's MDA (Mail Delivery Agent, usually
85 \fIsendmail\fR(8) but your system may use a different one such
86 as \fIsmail\fR, \fImmdf\fR, \fIexim\fR, \fIpostfix\fR, or \fIqmail\fR). All the
87 delivery-control mechanisms (such as \fI.forward\fR files) normally
88 available through your system MDA and local delivery agents will
89 therefore work automatically.
91 If no port 25 listener is available, but your fetchmail configuration
92 was told about a reliable local MDA, it will use that MDA for local
97 is available, it will assist you in setting up and editing a
98 fetchmailrc configuration. It runs under the X window system and
99 requires that the language Python and the Tk toolkit be present on your
100 system. If you are first setting up fetchmail for single-user mode, it
101 is recommended that you use Novice mode. Expert mode provides complete
102 control of fetchmail configuration, including the multidrop features.
103 In either case, the 'Autoprobe' button will tell you the most capable
104 protocol a given mailserver supports, and warn you of potential problems
107 .SH GENERAL OPERATION
110 is controlled by command-line options and a run control file,
111 .IR ~/.fetchmailrc\fR ,
112 the syntax of which we describe in a later section (this file is what
113 the \fIfetchmailconf\fR program edits). Command-line options override
117 Each server name that you specify following the options on the
118 command line will be queried. If you don't specify any servers
119 on the command line, each 'poll' entry in your
121 file will be queried.
123 To facilitate the use of
125 in scripts and pipelines, it returns an appropriate exit code upon
126 termination -- see EXIT CODES below.
128 The following options modify the behavior of \fIfetchmail\fR. It is
129 seldom necessary to specify any of these once you have a
130 working \fI.fetchmailrc\fR file set up.
132 Almost all options have a corresponding keyword which can be used to
137 Some special options are not covered here, but are documented instead
138 in sections on AUTHENTICATION and DAEMON MODE which follow.
142 Displays the version information for your copy of
144 No mail fetch is performed.
145 Instead, for each server specified, all the option information
146 that would be computed if
148 were connecting to that server is displayed. Any non-printables in
149 passwords or other string names are shown as backslashed C-like
150 escape sequences. This option is useful for verifying that your
151 options are set the way you want them.
154 Return a status code to indicate whether there is mail waiting,
155 without actually fetching or deleting mail (see EXIT CODES below).
156 This option turns off daemon mode (in which it would be useless). It
157 doesn't play well with queries to multiple sites, and doesn't work
158 with ETRN or ODMR. It will return a false positive if you leave read but
159 undeleted mail in your server mailbox and your fetch protocol can't
160 tell kept messages from new ones. This means it will work with IMAP,
161 not work with POP2, and may occasionally flake out under POP3.
164 Silent mode. Suppresses all progress/status messages that are
165 normally echoed to standard output during a fetch (but does not
166 suppress actual error messages). The --verbose option overrides this.
169 Verbose mode. All control messages passed between
171 and the mailserver are echoed to stdout. Overrides --silent.
172 Doubling this option (-v -v) causes extra diagnostic information
178 Retrieve both old (seen) and new messages from the mailserver. The
179 default is to fetch only messages the server has not marked seen.
180 Under POP3, this option also forces the use of RETR rather than TOP.
181 Note that POP2 retrieval behaves as though --all is always on (see
182 RETRIEVAL FAILURE MODES below) and this option does not work with ETRN
187 Keep retrieved messages on the remote mailserver. Normally, messages
188 are deleted from the folder on the mailserver after they have been retrieved.
191 option causes retrieved messages to remain in your folder on the
192 mailserver. This option does not work with ETRN or ODMR.
196 Delete retrieved messages from the remote mailserver. This
197 option forces retrieved mail to be deleted. It may be useful if
198 you have specified a default of \fBkeep\fR in your
199 \&\fI.fetchmailrc\fR. This option is forced on with ETRN and ODMR.
202 POP3/IMAP only. This is a dangerous option and can cause mail loss when
203 used improperly. It deletes old (seen) messages from the mailserver
204 before retrieving new messages. Warning: This can cause mail loss if
205 you check your mail with other clients than fetchmail, and cause
206 fetchmail to delete a message it had never fetched before. Similarly, if
207 your local MTA hangs and fetchmail is aborted, the next time you run
208 fetchmail, it will delete mail that was never delivered to you. You
209 should probably not use this option in your configuration file. What you
210 probably want is the default setting: if you don't specify '-k', then
211 fetchmail will automatically delete messages after successful
212 delivery. This option does not work with ETRN and ODMR.
215 POP3/IMAP only, since version 6.3.0. Delete oversized messages from the
216 mailserver before retrieving new messages. The size limit should be
217 separately sepecified with the --limit option. This option does not
218 work with ETRN or ODMR.
219 .SS Protocol and Query Options
221 .B \-p <proto> | \-\-proto <proto> | \-\-protocol <proto>
222 (Keyword: proto[col])
223 Specify the protocol to use when communicating with the remote
224 mailserver. If no protocol is specified, the default is AUTO.
226 may be one of the following:
229 Tries IMAP, POP3, and POP2 (skipping any of these for which support
230 has not been compiled in).
232 Post Office Protocol 2 (legacy, to be removed from future release)
234 Post Office Protocol 3
236 Use POP3 with old-fashioned MD5-challenge authentication.
238 Use POP3 with RPOP authentication.
240 Use POP3 with Kerberos V4 authentication on port 1109.
242 Use POP3 with Demon Internet's SDPS extensions.
244 IMAP2bis, IMAP4, or IMAP4rev1 (\fIfetchmail\fR autodetects their capabilities).
246 Use the ESMTP ETRN option.
248 Use the the On-Demand Mail Relay ESMTP profile.
251 All these alternatives work in basically the same way (communicating
252 with standard server daemons to fetch mail already delivered to a
253 mailbox on the server) except ETRN and ODMR. The ETRN mode
254 allows you to ask a compliant ESMTP server (such as BSD sendmail at
255 release 8.8.0 or higher) to immediately open a sender-SMTP connection
256 to your client machine and begin forwarding any items addressed to
257 your client machine in the server's queue of undelivered mail. The
258 ODMR mode requires an ODMR-capable server and works similarly to
259 ETRN, except that it does not require the client machine to have
264 Force UIDL use (effective only with POP3). Force client-side tracking
265 of 'newness' of messages (UIDL stands for "unique ID listing" and is
266 described in RFC1939). Use with 'keep' to use a mailbox as a baby
267 news drop for a group of users. The fact that seen messages are skipped
268 is logged, unless error logging is done through syslog while running in
269 daemon mode. Note that fetchmail may automatically enable this option
270 depending on upstream server capabilities. Note also that this option
271 may be removed and forced enabled in a future fetchmail version.
274 .B \-\-service <servicename>
275 (Keyword: service) Since version 6.3.0.
276 The service option permits you to specify a service name to connect to.
277 You can specify a decimal port number here, if your services database
278 lacks the required service-port assignments. See the FAQ item R12 and
279 the \-\-ssl documentation for details. This replaces the older \-\-port
282 .B \-P <portnumber> | \-\-port <portnumber>
284 Obsolete version of \-\-service that does not take service names.
286 this option may be removed from a future version.
288 .B \-\-principal <principal>
290 The principal option permits you to specify a service principal for
291 mutual authentication. This is applicable to POP3 or IMAP with Kerberos
294 .B \-t <seconds> | \-\-timeout <seconds>
296 The timeout option allows you to set a server-nonresponse
297 timeout in seconds. If a mailserver does not send a greeting message
298 or respond to commands for the given number of seconds,
299 \fIfetchmail\fR will hang up on it. Without such a timeout
300 \fIfetchmail\fR might hang up indefinitely trying to fetch mail from a
301 down host. This would be particularly annoying for a \fIfetchmail\fR
302 running in background. There is a default timeout which fetchmail\~-V
303 will report. If a given connection receives too many timeouts in
304 succession, fetchmail will consider it wedged and stop retrying,
305 the calling user will be notified by email if this happens.
307 .B \-\-plugin <command>
308 (Keyword: plugin) The plugin option allows you to use an external
309 program to establish the TCP connection. This is useful if you want
310 to use socks, SSL, ssh, or need some special firewalling setup. The
311 program will be looked up in $PATH and can optionally be passed the
312 hostname and port as arguments using "%h" and "%p" respectively (note
313 that the interpolation logic is rather primitive, and these token must
314 be bounded by whitespace or beginning of string or end of string).
315 Fetchmail will write to the plugin's stdin and read from the plugin's
318 .B \-\-plugout <command>
320 Identical to the plugin option above, but this one is used for the SMTP
321 connections (which will probably not need it, so it has been separated
324 .B \-r <name> | \-\-folder <name>
326 Causes a specified non-default mail folder on the mailserver (or
327 comma-separated list of folders) to be retrieved. The syntax of the
328 folder name is server-dependent. This option is not available under
332 (Keyword: tracepolls)
333 Tell fetchmail to poll trace information in the form 'polling %s
334 account %s' to the Received line it generates, where the %s parts are
335 replaced by the user's remote name and the poll label (the Received
336 header also normally includes the server's true name). This can be
337 used to facilitate mail filtering based on the account it is being
342 Causes the connection to the mail server to be encrypted via SSL. Connect
343 to the server using the specified base protocol over a connection secured
344 by SSL. SSL support must be present at the server.
346 If no port is specified, the connection is attempted to the well known
347 port of the SSL version of the base protocol. This is generally a
348 different port than the port used by the base protocol. For IMAP, this
349 is port 143 for the clear protocol and port 993 for the SSL secured
350 protocol, for POP3, it is port 110 for the cleartext and port 995 for
351 the encrypted variant.
353 If your system lacks the corresponding entries from /etc/services, see
354 the \-\-service option and specify the numeric port number as given in
355 the previous paragraph (unless your ISP had directed you to different
356 ports, which is uncommon however).
358 .B \-\-sslcert <name>
360 Specifies the file name of the client side public SSL certificate. Some
361 SSL encrypted servers may require client side keys and certificates for
362 authentication. In most cases, this is optional. This specifies
363 the location of the public key certificate to be presented to the server
364 at the time the SSL session is established. It is not required (but may
365 be provided) if the server does not require it. Some servers may
366 require it, some servers may request it but not require it, and some
367 servers may not request it at all. It may be the same file
368 as the private key (combined key and certificate file) but this is not
373 Specifies the file name of the client side private SSL key. Some SSL
374 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 private key used to sign transactions with 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 public key (combined key and certificate file) but this is not
382 recommended. If a password is required to unlock the key, it will be
383 prompted for at the time just prior to establishing the session to the
384 server. This can cause some complications in daemon mode.
386 .B \-\-sslproto <name>
388 Forces an SSL protocol. Possible values are '\fBssl2\fR',
389 \&'\fBssl3\fR', '\fBssl23\fR', and '\fBtls1\fR'. Try this if the default
390 handshake does not work for your server. To defeat automatic TLSv1
391 negotiation when the server advertises STARTTLS or STLS, use \fB''\fR or
392 \&'\fBssl23\fR'. The default is to try appropriate protocols depending
397 Causes fetchmail to strictly check the server certificate against a set of
398 local trusted certificates (see the \fBsslcertpath\fR option). If the server
399 certificate is not signed by one of the trusted ones (directly or indirectly),
400 the SSL connection will fail. This checking should prevent man-in-the-middle
401 attacks against the SSL connection. Note that CRLs are seemingly not currently
402 supported by OpenSSL in certificate verification! Your system clock should
403 be reasonably accurate when using this option!
405 .B \-\-sslcertpath <directory>
406 (Keyword: sslcertpath)
407 Sets the directory fetchmail uses to look up local certificates. The default
408 is your OpenSSL default one. The directory must be hashed as OpenSSL expects
409 it - every time you add or modify a certificate in the directory, you need
410 to use the \fBc_rehash\fR tool (which comes with OpenSSL in the tools/
413 .B \-\-sslfingerprint <fingerprint>
414 (Keyword: sslfingerprint)
415 Specify the fingerprint of the server key (an MD5 hash of the key) in
416 hexadecimal notation with colons separating groups of two digits. The letter
417 hex digits must be in upper case. This is the default format OpenSSL uses,
418 and the one fetchmail uses to report the fingerprint when an SSL connection
419 is established. When this is specified, fetchmail will compare the server key
420 fingerprint with the given one, and the connection will fail if they do not
421 match. This can be used to prevent man-in-the-middle attacks.
423 To obtain the fingerprint of a certificate stored in the file cert.pem,
427 openssl x509 -in cert.pem -noout -fingerprint
432 .SS Delivery Control Options
434 .B \-S <hosts> | \-\-smtphost <hosts>
435 (Keyword: smtp[host])
436 Specify a hunt list of hosts to forward mail to (one or more
437 hostnames, comma-separated). Hosts are tried in list order; the first
438 one that is up becomes the forwarding target for the current run.
439 The default depends on the authentication methods and protocols used on
440 the active servers. If Kerberos is used for authentication or the ODMR
441 or ETRN protocol is used for any active server, the FQDN of the machine
442 running fetchmail is used as a default for smtphost. Otherwise,
443 'localhost' is used as a default. Each hostname may have a port number
444 following the host name. The port number is separated from the host
445 name by a slash; the default port is 25 (or "smtp" under IPv6). If you
446 specify an absolute path name (beginning with a /), it will be
447 interpreted as the name of a UNIX socket accepting LMTP connections
448 (such as is supported by the Cyrus IMAP daemon)
452 --smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
455 This option can be used with ODMR, and will make fetchmail a relay
456 between the ODMR server and SMTP or LMTP receiver.
458 .B \-\-fetchdomains <hosts>
459 (Keyword: fetchdomains)
460 In ETRN or ODMR mode, this option specifies the list of domains the
461 server should ship mail for once the connection is turned around. The
462 default is the FQDN of the machine running
465 .B \-D <domain> | \-\-smtpaddress <domain>
466 (Keyword: smtpaddress) Specify the domain to be appended to addresses
467 in RCPT TO lines shipped to SMTP. The name of the SMTP server (as
468 specified by --smtphost, or defaulted to "localhost") is used when
469 this is not specified.
471 .B \-\-smtpname <user@domain>
473 Specify the domain and user to be put in RCPT TO lines shipped to SMTP.
474 The default user is the current local user.
476 .B \-Z <nnn> | \-\-antispam <nnn[, nnn]...>
478 Specifies the list of numeric SMTP errors that are to be interpreted
479 as a spam-block response from the listener. A value of -1 disables
480 this option. For the command-line option, the list values should
483 .B \-m <command> | \-\-mda <command>
484 (Keyword: mda) You can force mail to be passed to an MDA directly
485 (rather than forwarded to port 25) with the --mda or -m option. To
486 avoid losing mail, use this option only with MDAs like maildrop, procmail or
487 sendmail that return a nonzero status on disk-full and other
488 resource-exhaustion errors; the nonzero status tells fetchmail that
489 delivery failed and prevents the message from being deleted off the
490 server. If \fIfetchmail\fR is running as root, it sets its user id to
491 that of the target user while delivering mail through an MDA. Some
492 possible MDAs are "/usr/sbin/sendmail -i -f %F %T", "/usr/bin/deliver"
493 and "/usr/bin/procmail -d %T" (but the latter is usually redundant as
494 it's what SMTP listeners normally forward to). Local delivery
495 addresses will be inserted into the MDA command wherever you place a
496 %T; the mail message's From address will be inserted where you place
497 an %F. \fBDO NOT ENCLOSE THE %F OR %T STRING IN SINGLE QUOTES!\fR For
498 both %T and %F, fetchmail encloses the addresses in single quotes ('),
499 after removing any single quotes they may contain, before the MDA
500 command is passed to the shell. Do \fINOT\fR use an MDA invocation
501 like "sendmail -i -t" that dispatches on the contents of To/Cc/Bcc, it
502 will create mail loops and bring the just wrath of many postmasters
503 down upon your head. Also, do \fInot\fR try to combine multidrop
504 mode with an MDA such as procmail that can only accept one address;
509 Cause delivery via LMTP (Local Mail Transfer Protocol). A service
510 port \fImust\fR be explicitly specified (with a slash suffix) on each
511 host in the smtphost hunt list if this option is selected; the
512 default port 25 will (in accordance with RFC 2033) not be accepted.
514 .B \-\-bsmtp <filename>
516 Append fetched mail to a BSMTP file. This simply contains the SMTP
517 commands that would normally be generated by fetchmail when passing
518 mail to an SMTP listener daemon. An argument of '-' causes the mail
519 to be written to standard output. Note that fetchmail's
520 reconstruction of MAIL FROM and RCPT TO lines is not guaranteed
521 correct; the caveats discussed under THE USE AND ABUSE OF MULTIDROP
522 MAILBOXES below apply.
523 .SS Resource Limit Control Options
525 .B \-l <maxbytes> | \-\-limit <maxbytes>
526 (Keyword: limit) Takes a maximum octet size argument. Messages larger
527 than this size will not be fetched and will be left on the server (in
528 foreground sessions, the progress messages will note that they are
529 "oversized"). If the fetch protocol permits (in particular, under
530 IMAP or POP3 without the fetchall option) the message will not be
533 An explicit --limit of 0 overrides any limits set in your
534 run control file. This option is intended for those needing to
535 strictly control fetch time due to expensive and variable phone rates.
537 Combined with --limitflush, it can be used to delete oversized
538 messages waiting on a server. In daemon mode, oversize notifications
539 are mailed to the calling user (see the --warnings option). This
540 option does not work with ETRN or ODMR.
542 .B \-w <interval> | \-\-warnings <interval>
544 Takes an interval in seconds. When you call
546 with a 'limit' option in daemon mode, this controls the interval at
547 which warnings about oversized messages are mailed to the calling user
548 (or the user specified by the 'postmaster' option). One such
549 notification is always mailed at the end of the the first poll that
550 the oversized message is detected. Thereafter, renotification is
551 suppressed until after the warning interval elapses (it will take
552 place at the end of the first following poll).
554 .B \-b <count> | \-\-batchlimit <count>
555 (Keyword: batchlimit)
556 Specify the maximum number of messages that will be shipped to an SMTP
557 listener before the connection is deliberately torn down and rebuilt
558 (defaults to 0, meaning no limit). An explicit --batchlimit of 0
559 overrides any limits set in your run control file. While
560 \fBsendmail\fR(8) normally initiates delivery of a message immediately
561 after receiving the message terminator, some SMTP listeners are not so
562 prompt. MTAs like \fIsmail\fR(8) may wait till the
563 delivery socket is shut down to deliver. This may produce annoying
564 delays when \fIfetchmail\fR is processing very large batches. Setting
565 the batch limit to some nonzero size will prevent these delays. This
566 option does not work with ETRN or ODMR.
568 .B \-B <number> | \-\-fetchlimit <number>
569 (Keyword: fetchlimit)
570 Limit the number of messages accepted from a given server in a single
571 poll. By default there is no limit. An explicit --fetchlimit of 0
572 overrides any limits set in your run control file.
573 This option does not work with ETRN or ODMR.
575 .B \-\-fetchsizelimit <number>
576 (Keyword: fetchsizelimit)
577 Limit the number of sizes of messages accepted from a given server in
578 a single transaction. This option is useful in reducing the delay in
579 downloading the first mail when there are too many mails in the
580 mailbox. By default, the limit is 100. If set to 0, sizes of all
581 messages are downloaded at the start.
582 This option does not work with ETRN or ODMR. For POP3, the only valid
585 .B \-\-fastuidl <number>
587 Do a binary instead of linear search for the first unseen UID. Binary
588 search avoids downloading the UIDs of all mails. This saves time
589 (especially in daemon mode) where downloading the same set of UIDs in
590 each poll is a waste of bandwidth. The number 'n' indicates how rarely
591 a linear search should be done. In daemon mode, linear search is used
592 once followed by binary searches in 'n-1' polls if 'n' is greater than
593 1; binary search is always used if 'n' is 1; linear search is always
594 used if 'n' is 0. In non-daemon mode, binary search is used if 'n' is
595 1; otherwise linear search is used.
596 This option works with POP3 only.
598 .B \-e <count> | \-\-expunge <count>
600 Arrange for deletions to be made final after a given number of
601 messages. Under POP2 or POP3, fetchmail cannot make deletions final
602 without sending QUIT and ending the session -- with this option on,
603 fetchmail will break a long mail retrieval session into multiple
604 sub-sessions, sending QUIT after each sub-session. This is a good
605 defense against line drops on POP3 servers that do not do the
606 equivalent of a QUIT on hangup. Under IMAP,
608 normally issues an EXPUNGE command after each deletion in order to
609 force the deletion to be done immediately. This is safest when your
610 connection to the server is flaky and expensive, as it avoids
611 resending duplicate mail after a line hit. However, on large
612 mailboxes the overhead of re-indexing after every message can slam the
613 server pretty hard, so if your connection is reliable it is good to do
614 expunges less frequently. Also note that some servers enforce a delay
615 of a few seconds after each quit, so fetchmail may not be able to get
616 back in immediately after an expunge -- you may see "lock busy" errors
617 if this happens. If you specify this option to an integer N,
620 to only issue expunges on every Nth delete. An argument of zero
621 suppresses expunges entirely (so no expunges at all will be done until
622 the end of run). This option does not work with ETRN or ODMR.
623 .SS Authentication Options
625 .B \-u <name> | \-\-user <name> | \-\-username <name>
626 (Keyword: user[name])
627 Specifies the user identification to be used when logging in to the mailserver.
628 The appropriate user identification is both server and user-dependent.
629 The default is your login name on the client machine that is running
631 See USER AUTHENTICATION below for a complete description.
633 .B \-I <specification> | \-\-interface <specification>
635 Require that a specific interface device be up and have a specific local
636 or remote IPv4 (IPv6 is not supported by this option yet) address (or
637 range) before polling. Frequently \fIfetchmail\fP
638 is used over a transient point-to-point TCP/IP link established directly
639 to a mailserver via SLIP or PPP. That is a relatively secure channel.
640 But when other TCP/IP routes to the mailserver exist (e.g. when the link
641 is connected to an alternate ISP), your username and password may be
642 vulnerable to snooping (especially when daemon mode automatically polls
643 for mail, shipping a clear password over the net at predictable
644 intervals). The --interface option may be used to prevent this. When
645 the specified link is not up or is not connected to a matching IP
646 address, polling will be skipped. The format is:
649 interface/iii.iii.iii.iii[/mmm.mmm.mmm.mmm]
652 The field before the first slash is the interface name (i.e. sl0, ppp0
653 etc.). The field before the second slash is the acceptable IP address.
654 The field after the second slash is a mask which specifies a range of
655 IP addresses to accept. If no mask is present 255.255.255.255 is
656 assumed (i.e. an exact match). This option is currently only supported
657 under Linux and FreeBSD. Please see the
659 section for below for FreeBSD specific information.
661 Note that this option may be removed from a future fetchmail version.
663 .B \-M <interface> | \-\-monitor <interface>
665 Daemon mode can cause transient links which are automatically taken down
666 after a period of inactivity (e.g. PPP links) to remain up
667 indefinitely. This option identifies a system TCP/IP interface to be
668 monitored for activity. After each poll interval, if the link is up but
669 no other activity has occurred on the link, then the poll will be
670 skipped. However, when fetchmail is woken up by a signal, the
671 monitor check is skipped and the poll goes through unconditionally.
672 This option is currently only supported under Linux and FreeBSD.
677 options to work for non root users under FreeBSD, the fetchmail binary
678 must be installed SGID kmem. This would be a security hole, but
679 fetchmail runs with the effective GID set to that of the kmem group
681 when interface data is being collected.
683 Note that this option may be removed from a future fetchmail version.
686 (Keyword: auth[enticate])
687 This option permits you to specify an authentication type (see USER
688 AUTHENTICATION below for details). The possible values are \fBany\fR,
689 \&\fBpassword\fR, \fBkerberos_v5\fR, \fBkerberos\fR (or, for
690 excruciating exactness, \fBkerberos_v4\fR), \fBgssapi\fR,
691 \fBcram-md5\fR, \fBotp\fR, \fBntlm\fR, \fBmsn\fR (only for POP3) and
692 \fBssh\fR. When \fBany\fR (the default) is specified, fetchmail tries
693 first methods that don't require a password (GSSAPI, KERBEROS\ IV,
694 KERBEROS\ 5); then it looks for methods that mask your password
695 (CRAM-MD5, X-OTP - note that NTLM and MSN are not autoprobed for POP3
696 and MSN is only supported for POP3); and only if the server doesn't
697 support any of those will it ship your password en clair. Other values
698 may be used to force various authentication methods
699 (\fBssh\fR suppresses authentication and is thus good for IMAP PREAUTH).
700 Any value other than \fBpassword\fR, \fBcram-md5\fR, \fBntlm\fR,
701 \&\fBmsn\fR or \fBotp\fR suppresses fetchmail's normal inquiry for a
702 password. Specify \fBssh\fR when you are using an end-to-end secure
703 connection such as an ssh tunnel; specify \fBgssapi\fR or
704 \&\fBkerberos_v4\fR if you are using a protocol variant that employs
705 GSSAPI or K4. Choosing KPOP protocol automatically selects Kerberos
706 authentication. This option does not work with ETRN.
707 .SS Miscellaneous Options
709 .B \-f <pathname> | \-\-fetchmailrc <pathname>
710 Specify a non-default name for the
712 run control file. The pathname argument must be either "-" (a single
713 dash, meaning to read the configuration from standard input) or a
714 filename. Unless the --version option is also on, a named file
715 argument must have permissions no more open than 0600 (u=rw,g=,o=) or
718 .B \-i <pathname> | \-\-idfile <pathname>
720 Specify an alternate name for the .fetchids file used to save POP3
723 .B \-n | \-\-norewrite
724 (Keyword: no rewrite)
727 edits RFC-822 address headers (To, From, Cc, Bcc, and Reply-To) in
728 fetched mail so that any mail IDs local to the server are expanded to
729 full addresses (@ and the mailserver hostname are appended). This enables
730 replies on the client to get addressed correctly (otherwise your
731 mailer might think they should be addressed to local users on the
732 client machine!). This option disables the rewrite. (This option is
733 provided to pacify people who are paranoid about having an MTA edit
734 mail headers and want to know they can prevent it, but it is generally
735 not a good idea to actually turn off rewrite.)
736 When using ETRN or ODMR, the rewrite option is ineffective.
738 .B \-E <line> | \-\-envelope <line>
739 (Keyword: envelope; Multidrop only)
741 In the configuration file, an enhanced syntax is used:
743 .B envelope [<count>] <line>
745 This option changes the header
747 assumes will carry a copy of the mail's envelope address. Normally
748 this is 'X-Envelope-To' but as this header is not standard, practice
749 varies. See the discussion of multidrop address handling below. As a
750 special case, 'envelope "Received"' enables parsing of sendmail-style
751 Received lines. This is the default, and it should not be necessary
752 unless you have globally disabled Received parsing with 'no envelope'
753 in the \fI.fetchmailrc\fR file.
755 The optional count argument (only available in the configuration file)
756 determines how many header lines of this kind are skipped. A count of 1
757 means: skip the first, take the second. A count of 2 means: skip the
758 first and second, take the third, and so on.
760 .B \-Q <prefix> | \-\-qvirtual <prefix>
761 (Keyword: qvirtual; Multidrop only)
762 The string prefix assigned to this option will be removed from the user
763 name found in the header specified with the \fIenvelope\fR option
764 (\fIbefore\fR doing multidrop name mapping or localdomain checking,
765 if either is applicable). This option is useful if you are using
767 to collect the mail for an entire domain and your ISP (or your mail
768 redirection provider) is using qmail.
769 One of the basic features of qmail is the
773 message header. Whenever qmail delivers a message to a local mailbox
774 it puts the username and hostname of the envelope recipient on this
775 line. The major reason for this is to prevent mail loops. To set up
776 qmail to batch mail for a disconnected site the ISP-mailhost will have
777 normally put that site in its 'Virtualhosts' control file so it will
778 add a prefix to all mail addresses for this site. This results in mail
779 .\" The \&@\& tries to stop HTML converters from making a mailto URL here.
780 sent to 'username\&@\&userhost.userdom.dom.com' having a
781 \&'Delivered-To:' line of the form:
783 Delivered-To: mbox-userstr-username\&@\&userhost.userdom.dom.com
785 The ISP can make the 'mbox-userstr-' prefix anything they choose
786 but a string matching the user host name is likely.
787 By using the option 'envelope Delivered-To:' you can make fetchmail reliably
788 identify the original envelope recipient, but you have to strip the
789 \&'mbox-userstr-' prefix to deliver to the correct user.
790 This is what this option is for.
795 file, interpret any command-line options specified, and dump a
796 configuration report to standard output. The configuration report is
797 a data structure assignment in the language Python. This option
798 is meant to be used with an interactive
806 Removed before version 6.3.0, the required underlying inet6_apps library
807 had been discontinued and is no longer available.
809 .SH USER AUTHENTICATION AND ENCRYPTION
810 All modes except ETRN require authentication of the client to the server.
811 Normal user authentication in
813 is very much like the authentication mechanism of
815 The correct user-id and password depend upon the underlying security
816 system at the mailserver.
818 If the mailserver is a Unix machine on which you have an ordinary user
819 account, your regular login name and password are used with
821 If you use the same login name on both the server and the client machines,
822 you needn't worry about specifying a user-id with the
824 option \-\- the default behavior is to use your login name on the
825 client machine as the user-id on the server machine. If you use a
826 different login name on the server machine, specify that login name
829 option. e.g. if your login name is 'jsmith' on a machine named 'mailgrunt',
834 fetchmail -u jsmith mailgrunt
836 The default behavior of
838 is to prompt you for your mailserver password before the connection is
839 established. This is the safest way to use
841 and ensures that your password will not be compromised. You may also specify
842 your password in your
844 file. This is convenient when using
846 in daemon mode or with scripts.
847 .SS Using netrc files
849 If you do not specify a password, and
851 cannot extract one from your
853 file, it will look for a
855 file in your home directory before requesting one interactively; if an
856 entry matching the mailserver is found in that file, the password will
857 be used. Fetchmail first looks for a match on poll name; if it finds none,
858 it checks for a match on via name. See the
860 man page for details of the syntax of the
862 file. To show a practical example, a .netrc might look like
866 machine hermes.example.org
871 You can repeat this block with different user information if you need to
872 provide more than one password.
874 This feature may allow you to avoid duplicating password
875 information in more than one file.
877 On mailservers that do not provide ordinary user accounts, your user-id and
878 password are usually assigned by the server administrator when you apply for
879 a mailbox on the server. Contact your server administrator if you don't know
880 the correct user-id and password for your mailbox account.
883 Early versions of POP3 (RFC1081, RFC1225) supported a crude form of
884 independent authentication using the
886 file on the mailserver side. Under this RPOP variant, a fixed
887 per-user ID equivalent to a password was sent in clear over a link to
888 a reserved port, with the command RPOP rather than PASS to alert the
889 server that it should do special checking. RPOP is supported
892 (you can specify 'protocol RPOP' to have the program send 'RPOP'
893 rather than 'PASS') but its use is strongly discouraged. This
894 facility was vulnerable to spoofing and was withdrawn in RFC1460.
896 RFC1460 introduced APOP authentication. In this variant of POP3,
897 you register an APOP password on your server host (the program
898 to do this with on the server is probably called \fIpopauth\fR(8)). You
899 put the same password in your
903 logs in, it sends a cryptographically secure hash of your password and
904 the server greeting time to the server, which can verify it by
905 checking its authorization database.
906 .SS Alternate authentication forms
908 If your \fIfetchmail\fR was built with Kerberos support and you specify
909 Kerberos authentication (either with --auth or the \fI.fetchmailrc\fR
910 option \fBauthenticate kerberos_v4\fR) it will try to get a Kerberos
911 ticket from the mailserver at the start of each query. Note: if
912 either the pollname or via name is 'hesiod', fetchmail will try to use
913 Hesiod to look up the mailserver.
915 If you use POP3 or IMAP with GSSAPI authentication, \fIfetchmail\fR will
916 expect the server to have RFC1731- or RFC1734-conformant GSSAPI
917 capability, and will use it. Currently this has only been tested over
918 Kerberos V, so you're expected to already have a ticket-granting
919 ticket. You may pass a username different from your principal name
920 using the standard \fB--user\fR command or by the \fI.fetchmailrc\fR
923 If your IMAP daemon returns the PREAUTH response in its greeting line,
924 fetchmail will notice this and skip the normal authentication step.
925 This can be useful, e.g. if you start imapd explicitly using ssh.
926 In this case you can declare the authentication value 'ssh' on that
927 site entry to stop \fI.fetchmail\fR from asking you for a password
930 If you are using POP3, and the server issues a one-time-password
931 challenge conforming to RFC1938, \fIfetchmail\fR will use your
932 password as a pass phrase to generate the required response. This
933 avoids sending secrets over the net unencrypted.
935 Compuserve's RPA authentication (similar to APOP) is supported. If you
936 compile in the support, \fIfetchmail\fR will try to perform an RPA pass-phrase
937 authentication instead of sending over the password en clair if it
938 detects "@compuserve.com" in the hostname.
940 If you are using IMAP, Microsoft's NTLM authentication (used by Microsoft
941 Exchange) is supported. If you compile in the support, \fIfetchmail\fR
942 will try to perform an NTLM authentication (instead of sending over the
943 password en clair) whenever the server returns AUTH=NTLM in its
944 capability response. Specify a user option value that looks like
945 \&'user@domain': the part to the left of the @ will be passed as the
946 username and the part to the right as the NTLM domain.
947 .SS Secure Socket Layers (SSL)
949 You can access SSL encrypted services by specifying the --ssl option.
950 You can also do this using the "ssl" server option in the .fetchmailrc
951 file. With SSL encryption enabled, queries are initiated over a connection
952 after negotiating an SSL session. Some services, such as POP3 and IMAP,
953 have different well known ports defined for the SSL encrypted services.
954 The encrypted ports will be selected automatically when SSL is enabled and
955 no explicit port is specified.
957 When connecting to an SSL encrypted server, the server presents a certificate
958 to the client for validation. The certificate is checked to verify that
959 the common name in the certificate matches the name of the server being
960 contacted and that the effective and expiration dates in the certificate
961 indicate that it is currently valid. If any of these checks fail, a warning
962 message is printed, but the connection continues. The server certificate
963 does not need to be signed by any specific Certifying Authority and may
964 be a "self-signed" certificate.
966 Some SSL encrypted servers may request a client side certificate. A client
967 side public SSL certificate and private SSL key may be specified. If
968 requested by the server, the client certificate is sent to the server for
969 validation. Some servers may require a valid client certificate and may
970 refuse connections if a certificate is not provided or if the certificate
971 is not valid. Some servers may require client side certificates be signed
972 by a recognized Certifying Authority. The format for the key files and
973 the certificate files is that required by the underlying SSL libraries
974 (OpenSSL in the general case).
976 A word of care about the use of SSL: While above mentioned
977 setup with self-signed server certificates retrieved over the wires
978 can protect you from a passive eavesdropper it doesn't help against an
979 active attacker. It's clearly an improvement over sending the
980 passwords in clear but you should be aware that a man-in-the-middle
981 attack is trivially possible (in particular with tools such as dsniff,
982 http://www.monkey.org/~dugsong/dsniff/). Use of an ssh tunnel (see
983 below for some examples) is preferable if you care seriously about the
984 security of your mailbox.
988 also supports authentication to the ESMTP server on the client side
989 according to RFC 2554. You can specify a name/password pair to be
990 used with the keywords 'esmtpname' and 'esmtppassword'; the former
991 defaults to the username of the calling user.
995 .B \-\-daemon <interval>
1000 in daemon mode. You must specify a numeric argument which is a
1001 polling interval in seconds.
1005 puts itself in background and runs forever, querying each specified
1006 host and then sleeping for the given polling interval.
1012 will, therefore, poll all the hosts described in your
1014 file (except those explicitly excluded with the 'skip' verb) once
1015 every fifteen minutes.
1017 It is possible to set a polling interval
1020 file by saying 'set daemon <interval>', where <interval> is an
1021 integer number of seconds. If you do this, fetchmail will always
1022 start in daemon mode unless you override it with the command-line
1023 option --daemon 0 or -d0.
1025 Only one daemon process is permitted per user; in daemon mode,
1027 makes a per-user lockfile to guarantee this.
1029 Normally, calling fetchmail with a daemon in the background sends a
1030 wake-up signal to the daemon, forcing it to poll mailservers
1031 immediately. (The wake-up signal is SIGHUP if fetchmail is running as
1032 root, SIGUSR1 otherwise.) The wake-up action also clears any 'wedged'
1033 flags indicating that connections have wedged due to failed
1034 authentication or multiple timeouts.
1038 will kill a running daemon process instead of waking it up (if there
1039 is no such process, \fIfetchmail\fP will notify you.
1040 If the \-\-quit option appears last on the command line, \fIfetchmail\fP
1041 will kill the running daemon process and then quit. Otherwise,
1042 \fIfetchmail\fP will first kill a running daemon process and then
1043 continue running with the other options.
1048 .B \-\-logfile <filename>
1049 option (keyword: set logfile) is only effective when fetchmail is
1050 detached. This option allows you to redirect status messages
1051 into a specified logfile (follow the option with the logfile name). The
1052 logfile is opened for append, so previous messages aren't deleted. This
1053 is primarily useful for debugging configurations.
1057 option (keyword: set syslog) allows you to redirect status and error
1058 messages emitted to the
1060 system daemon if available.
1061 Messages are logged with an id of \fBfetchmail\fR, the facility \fBLOG_MAIL\fR,
1062 and priorities \fBLOG_ERR\fR, \fBLOG_ALERT\fR or \fBLOG_INFO\fR.
1063 This option is intended for logging status and error messages which
1064 indicate the status of the daemon and the results while fetching mail
1066 Error messages for command line options and parsing the \fI.fetchmailrc\fR
1067 file are still written to stderr, or to the specified log file.
1070 option turns off use of
1072 assuming it's turned on in the
1077 .B \-\-logfile <file>
1084 option suppresses backgrounding and detachment of the
1085 daemon process from its control terminal. This is useful
1086 for debugging or when fetchmail runs as the child of a supervisor
1091 Note that this also causes the logfile option to be
1092 ignored (though perhaps it shouldn't).
1094 Note that while running in daemon mode polling a POP2 or IMAP2bis server,
1095 transient errors (such as DNS failures or sendmail delivery refusals)
1096 may force the fetchall option on for the duration of the next polling
1097 cycle. This is a robustness feature. It means that if a message is
1098 fetched (and thus marked seen by the mailserver) but not delivered
1099 locally due to some transient error, it will be re-fetched during the
1100 next poll cycle. (The IMAP logic doesn't delete messages until
1101 they're delivered, so this problem does not arise.)
1103 If you touch or change the
1105 file while fetchmail is running in daemon mode, this will be detected
1106 at the beginning of the next poll cycle. When a changed
1108 is detected, fetchmail rereads it and restarts from scratch (using
1109 exec(2); no state information is retained in the new instance). Note also
1110 that if you break the
1112 file's syntax, the new instance will softly and silently vanish away
1115 .SH ADMINISTRATIVE OPTIONS
1118 .B \-\-postmaster <name>
1119 option (keyword: set postmaster) specifies the last-resort username to
1120 which multidrop mail is to be forwarded if no matching local recipient
1121 can be found. It is also used as destination of undeliverable mail if
1122 the 'bouncemail' global option is off and additionally for spam-blocked
1123 mail if the 'bouncemail' global option is off and the 'spambounce'
1124 global option is on. This option defaults to the user who invoked
1126 If the invoking user is root, then the default of this option is
1127 the user 'postmaster'. Setting postmaster to the empty string causes
1128 such mail as described above to be discarded - this however is usually a
1130 See also the description of the 'FETCHMAILUSER' environment variable in
1131 the ENVIRONMENT section below.
1135 behaves like the "set no bouncemail" global option, which see.
1139 option (keyword: set invisible) tries to make fetchmail invisible.
1140 Normally, fetchmail behaves like any other MTA would -- it generates a
1141 Received header into each message describing its place in the chain of
1142 transmission, and tells the MTA it forwards to that the mail came from
1143 the machine fetchmail itself is running on. If the invisible option
1144 is on, the Received header is suppressed and fetchmail tries to spoof
1145 the MTA it forwards to into thinking it came directly from the
1150 option (keyword: set showdots) forces fetchmail to show progress dots
1151 even if the current tty is not stdout (for example logfiles).
1152 Starting with fetchmail version 5.3.0,
1153 progress dots are only shown on stdout by default.
1157 option, you can ask fetchmail to add information to the Received
1158 header on the form "polling {label} account {user}", where {label} is
1159 the account label (from the specified rcfile, normally ~/.fetchmailrc)
1160 and {user} is the username which is used to log on to the mail
1161 server. This header can be used to make filtering email where no
1162 useful header information is available and you want mail from
1163 different accounts sorted into different mailboxes (this could, for
1164 example, occur if you have an account on the same server running a
1165 mailing list, and are subscribed to the list using that account). The
1166 default is not adding any such header. In
1168 this is called 'tracepolls'.
1170 .SH RETRIEVAL FAILURE MODES
1171 The protocols \fIfetchmail\fR uses to talk to mailservers are next to
1172 bulletproof. In normal operation forwarding to port 25, no message is
1173 ever deleted (or even marked for deletion) on the host until the SMTP
1174 listener on the client side has acknowledged to \fIfetchmail\fR that
1175 the message has been either accepted for delivery or rejected due to a
1178 When forwarding to an MDA, however, there is more possibility
1179 of error. Some MDAs are 'safe' and reliably return a nonzero status
1180 on any delivery error, even one due to temporary resource limits.
1183 program is like this; so are most programs designed as mail transport
1188 These programs give back a reliable positive acknowledgement and
1189 can be used with the mda option with no risk of mail loss. Unsafe
1190 MDAs, though, may return 0 even on delivery failure. If this
1191 happens, you will lose mail.
1193 The normal mode of \fIfetchmail\fR is to try to download only 'new'
1194 messages, leaving untouched (and undeleted) messages you have already
1195 read directly on the server (or fetched with a previous \fIfetchmail
1196 --keep\fR). But you may find that messages you've already read on the
1197 server are being fetched (and deleted) even when you don't specify
1198 --all. There are several reasons this can happen.
1200 One could be that you're using POP2. The POP2 protocol includes no
1201 representation of 'new' or 'old' state in messages, so \fIfetchmail\fR
1202 must treat all messages as new all the time. But POP2 is obsolete, so
1205 A potential POP3 problem might be servers that insert messages
1206 in the middle of mailboxes (some VMS implementations of mail are
1207 rumored to do this). The \fIfetchmail\fR code assumes that new
1208 messages are appended to the end of the mailbox; when this is not true
1209 it may treat some old messages as new and vice versa. Using UIDL might
1210 fix this, otherwise, consider switching to IMAP.
1212 Yet another POP3 problem is that if they can't make tempfiles in the
1213 user's home directory, some POP3 servers will hand back an
1214 undocumented response that causes fetchmail to spuriously report "No
1217 The IMAP code uses the presence or absence of the server flag \eSeen
1218 to decide whether or not a message is new. This isn't the right thing
1219 to do, fetchmail should check the UIDVALIDITY and use UID, but it
1220 doesn't do that yet. Under Unix, it counts on your IMAP server to notice
1221 the BSD-style Status flags set by mail user agents and set the \eSeen
1222 flag from them when appropriate. All Unix IMAP servers we know of do
1223 this, though it's not specified by the IMAP RFCs. If you ever trip over
1224 a server that doesn't, the symptom will be that messages you have
1225 already read on your host will look new to the server. In this
1226 (unlikely) case, only messages you fetched with \fIfetchmail --keep\fR
1227 will be both undeleted and marked old.
1229 In ETRN and ODMR modes, \fIfetchmail\fR does not actually retrieve messages;
1230 instead, it asks the server's SMTP listener to start a queue flush
1231 to the client via SMTP. Therefore it sends only undelivered messages.
1234 Many SMTP listeners allow administrators to set up 'spam filters' that
1235 block unsolicited email from specified domains. A MAIL FROM or DATA line that
1236 triggers this feature will elicit an SMTP response which
1237 (unfortunately) varies according to the listener.
1241 return an error code of 571.
1243 According to RFC2821, the correct thing to return in this situation is
1244 550 "Requested action not taken: mailbox unavailable" (the draft adds
1245 "[E.g., mailbox not found, no access, or command rejected for policy
1248 Older versions of the
1250 MTA return 501 "Syntax error in parameters or arguments".
1254 MTA runs 554 as an antispam response.
1257 may reject code with a 500 response (followed by an enhanced status
1258 code that contains more information).
1262 treats as antispam responses and discards
1263 the message can be set with the 'antispam' option. This is one of the
1265 three circumstance under which fetchmail ever discards mail (the others
1266 are the 552 and 553 errors described below, and the suppression of
1267 multidropped messages with a message-ID already seen).
1271 is fetching from an IMAP server, the antispam response will be detected and
1272 the message rejected immediately after the headers have been fetched,
1273 without reading the message body. Thus, you won't pay for downloading
1274 spam message bodies.
1276 By default, the list of antispam responses is empty.
1278 If the \fIspambounce\fR global option is on, mail that is spam-blocked
1279 triggers an RFC1892/RFC1894 bounce message informing the originator that
1280 we do not accept mail from it. See also BUGS.
1282 .SH SMTP/ESMTP ERROR HANDLING
1283 Besides the spam-blocking described above, fetchmail takes special
1284 actions on the following SMTP/ESMTP error responses
1286 452 (insufficient system storage)
1287 Leave the message in the server mailbox for later retrieval.
1289 552 (message exceeds fixed maximum message size)
1290 Delete the message from the server. Send bounce-mail to the
1293 553 (invalid sending domain)
1294 Delete the message from the server. Don't even try to send
1295 bounce-mail to the originator.
1297 Other errors trigger bounce mail back to the originator. See also BUGS.
1299 .SH THE RUN CONTROL FILE
1300 The preferred way to set up fetchmail is to write a
1301 \&\fI.fetchmailrc\fR file in your home directory (you may do this
1302 directly, with a text editor, or indirectly via \fIfetchmailconf\fR).
1303 When there is a conflict between the command-line arguments and the
1304 arguments in this file, the command-line arguments take precedence.
1306 To protect the security of your passwords,
1307 your \fI~/.fetchmailrc\fR may not normally have more than 0600 (u=rw,g=,o=) permissions;
1309 will complain and exit otherwise (this check is suppressed when
1312 You may read the \fI.fetchmailrc\fR file as a list of commands to
1315 is called with no arguments.
1316 .SS Run Control Syntax
1318 Comments begin with a '#' and extend through the end of the line.
1319 Otherwise the file consists of a series of server entries or global
1320 option statements in a free-format, token-oriented syntax.
1322 There are four kinds of tokens: grammar keywords, numbers
1323 (i.e. decimal digit sequences), unquoted strings, and quoted strings.
1324 A quoted string is bounded by double quotes and may contain
1325 whitespace (and quoted digits are treated as a string). An unquoted
1326 string is any whitespace-delimited token that is neither numeric, string
1327 quoted nor contains the special characters ',', ';', ':', or '='.
1329 Any amount of whitespace separates tokens in server entries, but is
1330 otherwise ignored. You may use standard C-style escapes (\en, \et,
1331 \eb, octal, and hex) to embed non-printable characters or string
1332 delimiters in strings.
1334 Each server entry consists of one of the keywords 'poll' or 'skip',
1335 followed by a server name, followed by server options, followed by any
1336 number of user descriptions. Note: the most common cause of syntax
1337 errors is mixing up user and server options.
1339 For backward compatibility, the word 'server' is a synonym for 'poll'.
1341 You can use the noise keywords 'and', 'with',
1342 \&'has', 'wants', and 'options' anywhere in an entry to make
1343 it resemble English. They're ignored, but but can make entries much
1344 easier to read at a glance. The punctuation characters ':', ';' and
1345 \&',' are also ignored.
1348 The 'poll' verb tells fetchmail to query this host when it is run with
1349 no arguments. The 'skip' verb tells
1351 not to poll this host unless it is explicitly named on the command
1352 line. (The 'skip' verb allows you to experiment with test entries
1353 safely, or easily disable entries for hosts that are temporarily down.)
1355 .SS Keyword/Option Summary
1356 Here are the legal options. Keyword suffixes enclosed in
1357 square brackets are optional. Those corresponding to short command-line
1358 options are followed by '-' and the appropriate option letter. If
1359 option is only relevant to a single mode of operation, it is noted as
1360 's' or 'm' for singledrop- or multidrop-mode, respectively.
1362 Here are the legal global options:
1366 Keyword Opt Mode Function
1369 Set a background poll interval in seconds.
1371 set postmaster \& \& T{
1372 Give the name of the last-resort mail recipient (default: user running
1373 fetchmail, "postmaster" if run by the root user)
1375 set bouncemail \& \& T{
1376 Direct error mail to the sender (default)
1378 set no bouncemail \& \& T{
1379 Direct error mail to the local postmaster (as per the 'postmaster'
1380 global option above).
1382 set no spambounce \& \& T{
1383 Do not bounce spam-blocked mail (default).
1385 set spambounce \& \& T{
1386 Bounce blocked spam-blocked mail (as per the 'antispam' user option)
1387 back to the destination as indicated by the 'bouncemail' global option.
1388 Warning: Do not use this to bounce spam back to the sender - most spam
1389 is sent with false sender address and thus this option hurts innocent
1392 set logfile -L \& T{
1393 Name of a file to append error and status messages to.
1396 Name of the file to store UID lists in.
1399 Do error logging through syslog(3).
1401 set no syslog \& \& T{
1402 Turn off error logging through syslog(3). (default)
1404 set properties \& \& T{
1405 String value that is ignored by fetchmail (may be used by extension
1410 Here are the legal server options:
1414 Keyword Opt Mode Function
1417 Specify DNS name of mailserver, overriding poll name
1420 Specify protocol (case insensitive):
1421 POP2, POP3, IMAP, APOP, KPOP
1423 local[domains] \& m T{
1424 Specify domain(s) to be regarded as local
1427 Specify TCP/IP service port (obsolete, use 'service' instead).
1430 Specify service name (a numeric value is also allowed and
1431 considered a TCP/IP port number).
1433 auth[enticate] \& \& T{
1434 Set authentication type (default 'any')
1437 Server inactivity timeout in seconds (default 300)
1440 Specify envelope-address header name
1443 Disable looking for envelope address
1446 Qmail virtual domain prefix to remove from user name
1449 Specify alternate DNS names of mailserver
1452 specify IP interface(s) that must be up for server poll to take place
1455 Specify IP address to monitor for activity
1458 Specify command through which to make server connections.
1461 Specify command through which to make listener connections.
1464 Enable DNS lookup for multidrop (default)
1467 Disable DNS lookup for multidrop
1470 Do comparison by IP address for multidrop
1472 no checkalias \& m T{
1473 Do comparison by name for multidrop (default)
1476 Force POP3 to use client-side UIDLs (recommended)
1479 Turn off POP3 use of client-side UIDLs (default)
1482 Only check this site every N poll cycles; N is a numeric argument.
1485 Add poll tracing information to the Received header
1488 Set Kerberos principal (only useful with imap and kerberos)
1491 Set name for RFC2554 authentication to the ESMTP server.
1493 esmtppassword \& \& T{
1494 Set password for RFC2554 authentication to the ESMTP server.
1498 Here are the legal user options:
1502 Keyword Opt Mode Function
1505 Set remote user name
1506 (local user name if name followed by 'here')
1509 Connect local and remote user names
1512 Connect local and remote user names
1515 Specify remote account password
1518 Connect to server over the specified base protocol using SSL encryption
1521 Specify file for client side public SSL certificate
1524 Specify file for client side private SSL key
1527 Force ssl protocol for connection
1530 Specify remote folder to query
1533 Specify smtp host(s) to forward to
1535 fetchdomains \& m T{
1536 Specify domains for which mail should be fetched
1538 smtpaddress -D \& T{
1539 Specify the domain to be put in RCPT TO lines
1542 Specify the user and domain to be put in RCPT TO lines
1545 Specify what SMTP returns are interpreted as spam-policy blocks
1548 Specify MDA for local delivery
1551 Specify BSMTP batch file to append to
1554 Command to be executed before each connection
1556 postconnect \& \& T{
1557 Command to be executed after each connection
1560 Don't delete seen messages from server
1563 Flush all seen messages before querying (DANGEROUS)
1566 Flush all oversized messages before querying
1569 Fetch all messages whether seen or not
1572 Rewrite destination addresses for reply (default)
1575 Strip carriage returns from ends of lines
1578 Force carriage returns at ends of lines
1581 Force BODY=8BITMIME to ESMTP listener
1584 Strip Status and X-Mozilla-Status lines out of incoming mail
1586 dropdelivered \& \& T{
1587 Strip Delivered-To lines out of incoming mail
1590 Convert quoted-printable to 8-bit in MIME messages
1593 Idle waiting for new messages after each poll (IMAP only)
1596 Delete seen messages from server (default)
1599 Don't flush all seen messages before querying (default)
1601 no fetchall \& \& T{
1602 Retrieve only new messages (default)
1605 Don't rewrite headers
1608 Don't strip carriage returns (default)
1611 Don't force carriage returns at EOL (default)
1613 no pass8bits \& \& T{
1614 Don't force BODY=8BITMIME to ESMTP listener (default)
1616 no dropstatus \& \& T{
1617 Don't drop Status headers (default)
1619 no dropdelivered \& \& T{
1620 Don't drop Delivered-To headers (default)
1622 no mimedecode \& \& T{
1623 Don't convert quoted-printable to 8-bit in MIME messages (default)
1626 Don't idle waiting for new messages after each poll (IMAP only)
1629 Set message size limit
1632 Set message size warning interval
1635 Max # messages to forward in single connect
1638 Max # messages to fetch in single connect
1640 fetchsizelimit \& \& T{
1641 Max # message sizes to fetch in single transaction
1644 Use binary search for first unseen message (POP3 only)
1647 Perform an expunge on every #th message (IMAP and POP3 only)
1650 String value is ignored by fetchmail (may be used by extension scripts)
1654 Remember that all user options must \fIfollow\fR all server options.
1656 In the .fetchmailrc file, the 'envelope' string argument may be
1657 preceded by a whitespace-separated number. This number, if specified,
1658 is the number of such headers to skip over (that is, an argument of 1
1659 selects the second header of the given type). This is sometime useful
1660 for ignoring bogus envelope headers created by an ISP's local delivery
1661 agent or internal forwards (through mail inspection systems, for
1663 .SS Keywords Not Corresponding To Option Switches
1665 The 'folder' and 'smtphost' options (unlike their command-line
1666 equivalents) can take a space- or comma-separated list of names
1669 All options correspond to the obvious command-line arguments, except
1670 the following: 'via', 'interval', 'aka', 'is', 'to', 'dns'/'no dns',
1671 \&'checkalias'/'no checkalias', 'password', 'preconnect', 'postconnect',
1672 \&'localdomains', 'stripcr'/'no stripcr', 'forcecr'/'no forcecr',
1673 \&'pass8bits'/'no pass8bits' 'dropstatus/no dropstatus',
1674 \&'dropdelivered/no dropdelivered', 'mimedecode/no mimedecode', 'idle/no
1675 idle', and 'no envelope'.
1677 The 'via' option is for if you want to have more
1678 than one configuration pointing at the same site. If it is present,
1679 the string argument will be taken as the actual DNS name of the
1680 mailserver host to query.
1681 This will override the argument of poll, which can then simply be a
1682 distinct label for the configuration (e.g. what you would give on the
1683 command line to explicitly query this host).
1685 The 'interval' option (which takes a numeric argument) allows you to poll a
1686 server less frequently than the basic poll interval. If you say
1687 \&'interval N' the server this option is attached to will only be
1688 queried every N poll intervals.
1690 The 'is' or 'to' keywords associate the following local (client)
1691 name(s) (or server-name to client-name mappings separated by =) with
1692 the mailserver user name in the entry. If an is/to list has '*' as
1693 its last name, unrecognized names are simply passed through.
1695 A single local name can be used to support redirecting your mail when
1696 your username on the client machine is different from your name on the
1697 mailserver. When there is only a single local name, mail is forwarded
1698 to that local username regardless of the message's Received, To, Cc,
1699 and Bcc headers. In this case
1701 never does DNS lookups.
1703 When there is more than one local name (or name mapping) the
1704 \fIfetchmail\fR code does look at the Received, To, Cc, and Bcc
1705 headers of retrieved mail (this is 'multidrop mode'). It looks for
1706 addresses with hostname parts that match your poll name or your 'via',
1707 \&'aka' or 'localdomains' options, and usually also for hostname parts
1708 which DNS tells it are aliases of the mailserver. See the discussion
1709 of 'dns', 'checkalias', 'localdomains', and 'aka' for details on how
1710 matching addresses are handled.
1712 If \fIfetchmail\fR cannot match any mailserver usernames or
1713 localdomain addresses, the mail will be bounced.
1714 Normally it will be bounced to the sender, but if the 'bouncemail'
1715 global option is off, the mail will go to the local postmaster instead.
1716 (see the 'postmaster' global option). See also BUGS.
1718 The 'dns' option (normally on) controls the way addresses from
1719 multidrop mailboxes are checked. On, it enables logic to check each
1720 host address that doesn't match an 'aka' or 'localdomains' declaration
1721 by looking it up with DNS. When a mailserver username is recognized
1722 attached to a matching hostname part, its local mapping is added to
1723 the list of local recipients.
1725 The 'checkalias' option (normally off) extends the lookups performed
1726 by the 'dns' keyword in multidrop mode, providing a way to cope with
1727 remote MTAs that identify themselves using their canonical name, while
1728 they're polled using an alias.
1729 When such a server is polled, checks to extract the envelope address
1732 reverts to delivery using the To/Cc/Bcc headers (See below
1733 \&'Header vs. Envelope addresses').
1734 Specifying this option instructs
1736 to retrieve all the IP addresses associated with both the poll name
1737 and the name used by the remote MTA and to do a comparison of the IP
1738 addresses. This comes in handy in situations where the remote server
1739 undergoes frequent canonical name changes, that would otherwise
1740 require modifications to the rcfile. 'checkalias' has no effect if
1741 \&'no dns' is specified in the rcfile.
1743 The 'aka' option is for use with multidrop mailboxes. It allows you
1744 to pre-declare a list of DNS aliases for a server. This is an
1745 optimization hack that allows you to trade space for speed. When
1747 while processing a multidrop mailbox, grovels through message headers
1748 looking for names of the mailserver, pre-declaring common ones can
1749 save it from having to do DNS lookups. Note: the names you give
1750 as arguments to 'aka' are matched as suffixes -- if you specify
1751 (say) 'aka netaxs.com', this will match not just a hostname
1752 netaxs.com, but any hostname that ends with '.netaxs.com'; such as
1753 (say) pop3.netaxs.com and mail.netaxs.com.
1755 The 'localdomains' option allows you to declare a list of domains
1756 which fetchmail should consider local. When fetchmail is parsing
1757 address lines in multidrop modes, and a trailing segment of a host
1758 name matches a declared local domain, that address is passed through
1759 to the listener or MDA unaltered (local-name mappings are \fInot\fR
1762 If you are using 'localdomains', you may also need to specify \&'no
1763 envelope', which disables \fIfetchmail\fR's normal attempt to deduce
1764 an envelope address from the Received line or X-Envelope-To header or
1765 whatever header has been previously set by 'envelope'. If you set 'no
1766 envelope' in the defaults entry it is possible to undo that in
1767 individual entries by using 'envelope <string>'. As a special case,
1768 \&'envelope "Received"' restores the default parsing of
1771 The \fBpassword\fR option requires a string argument, which is the password
1772 to be used with the entry's server.
1774 The 'preconnect' keyword allows you to specify a shell command to be
1775 executed just before each time
1777 establishes a mailserver connection. This may be useful if you are
1778 attempting to set up secure POP connections with the aid of
1780 If the command returns a nonzero status, the poll of that mailserver
1783 Similarly, the 'postconnect' keyword similarly allows you to specify a
1784 shell command to be executed just after each time a mailserver
1785 connection is taken down.
1787 The 'forcecr' option controls whether lines terminated by LF only are
1788 given CRLF termination before forwarding. Strictly speaking RFC821
1789 requires this, but few MTAs enforce the requirement it so this option
1790 is normally off (only one such MTA, qmail, is in significant use at
1793 The 'stripcr' option controls whether carriage returns are stripped
1794 out of retrieved mail before it is forwarded. It is normally not
1795 necessary to set this, because it defaults to 'on' (CR stripping
1796 enabled) when there is an MDA declared but 'off' (CR stripping
1797 disabled) when forwarding is via SMTP. If 'stripcr' and 'forcecr' are
1798 both on, 'stripcr' will override.
1800 The 'pass8bits' option exists to cope with Microsoft mail programs that
1801 stupidly slap a "Content-Transfer-Encoding: 7bit" on everything. With
1802 this option off (the default) and such a header present,
1804 declares BODY=7BIT to an ESMTP-capable listener; this causes problems for
1805 messages actually using 8-bit ISO or KOI-8 character sets, which will
1806 be garbled by having the high bits of all characters stripped. If
1807 \&'pass8bits' is on,
1809 is forced to declare BODY=8BITMIME to any ESMTP-capable listener. If
1810 the listener is 8-bit-clean (as all the major ones now are) the right
1811 thing will probably result.
1813 The 'dropstatus' option controls whether nonempty Status and
1814 X-Mozilla-Status lines are retained in fetched mail (the default) or
1815 discarded. Retaining them allows your MUA to see what messages (if
1816 any) were marked seen on the server. On the other hand, it can
1817 confuse some new-mail notifiers, which assume that anything with a
1818 Status line in it has been seen. (Note: the empty Status lines
1819 inserted by some buggy POP servers are unconditionally discarded.)
1821 The 'dropdelivered' option controls whether Delivered-To headers will
1822 be kept in fetched mail (the default) or discarded. These headers are
1823 added by Qmail and Postfix mailservers in order to avoid mail loops but
1824 may get in your way if you try to "mirror" a mailserver within the same
1825 domain. Use with caution.
1827 The 'mimedecode' option controls whether MIME messages using the
1828 quoted-printable encoding are automatically converted into pure 8-bit
1829 data. If you are delivering mail to an ESMTP-capable, 8-bit-clean
1830 listener (that includes all of the major MTAs like sendmail), then
1831 this will automatically convert quoted-printable message headers and
1832 data into 8-bit data, making it easier to understand when reading
1833 mail. If your e-mail programs know how to deal with MIME messages,
1834 then this option is not needed. The mimedecode option is off by
1835 default, because doing RFC2047 conversion on headers throws away
1836 character-set information and can lead to bad results if the encoding
1837 of the headers differs from the body encoding.
1839 The 'idle' option is intended to be used with IMAP servers supporting
1840 the RFC2177 IDLE command extension, but does not strictly require it.
1841 If it is enabled, and fetchmail detects that IDLE is supported, an
1842 IDLE will be issued at the end of each poll. This will tell the IMAP
1843 server to hold the connection open and notify the client when new mail
1844 is available. If IDLE is not supported, fetchmail will simulate it by
1845 periodically issuing NOOP. If you need to poll a link frequently, IDLE
1846 can save bandwidth by eliminating TCP/IP connects and LOGIN/LOGOUT
1847 sequences. On the other hand, an IDLE connection will eat almost all
1848 of your fetchmail's time, because it will never drop the connection
1849 and allow other pools to occur unless the server times out the IDLE.
1850 It also doesn't work with multiple folders; only the first folder will
1854 The 'properties' option is an extension mechanism. It takes a string
1855 argument, which is ignored by fetchmail itself. The string argument may be
1856 used to store configuration information for scripts which require it.
1857 In particular, the output of '--configdump' option will make properties
1858 associated with a user entry readily available to a Python script.
1860 .SS Miscellaneous Run Control Options
1861 The words 'here' and 'there' have useful English-like
1862 significance. Normally 'user eric is esr' would mean that
1863 mail for the remote user 'eric' is to be delivered to 'esr',
1864 but you can make this clearer by saying 'user eric there is esr here',
1865 or reverse it by saying 'user esr here is eric there'
1867 Legal protocol identifiers for use with the 'protocol' keyword are:
1871 pop2 (or POP2) (legacy, to be removed from future release)
1880 Legal authentication types are 'any', 'password', 'kerberos',
1881 \&'kerberos_v4', 'kerberos_v5' and 'gssapi', 'cram-md5', 'otp', 'msn'
1882 (only for POP3), 'ntlm', 'ssh'. The 'password' type specifies
1883 authentication by normal transmission of a password (the password may be
1884 plain text or subject to protocol-specific encryption as in APOP);
1885 \&'kerberos' tells \fIfetchmail\fR to try to get a Kerberos ticket at the
1886 start of each query instead, and send an arbitrary string as the
1887 password; and 'gssapi' tells fetchmail to use GSSAPI authentication.
1888 See the description of the 'auth' keyword for more.
1890 Specifying 'kpop' sets POP3 protocol over port 1109 with Kerberos V4
1891 authentication. These defaults may be overridden by later options.
1893 There are some global option statements: 'set logfile'
1894 followed by a string sets the same global specified by --logfile. A
1895 command-line --logfile option will override this. Note that --logfile is
1896 only effective if fetchmail detaches itself from the terminal. Also,
1897 'set daemon' sets the poll interval as --daemon does. This can be
1898 overridden by a command-line --daemon option; in particular --daemon 0
1899 can be used to force foreground operation. The 'set postmaster'
1900 statement sets the address to which multidrop mail defaults if there are
1901 no local matches. Finally, 'set syslog' sends log messages to
1904 .SH INTERACTION WITH RFC 822
1905 When trying to determine the originating address of a message,
1906 fetchmail looks through headers in the following order:
1910 Resent-Sender: (ignored if it doesn't contain an @ or !)
1911 Sender: (ignored if it doesn't contain an @ or !)
1918 The originating address is used for logging, and to set the MAIL FROM
1919 address when forwarding to SMTP. This order is intended to cope
1920 gracefully with receiving mailing list messages in multidrop mode. The
1921 intent is that if a local address doesn't exist, the bounce message
1922 won't be returned blindly to the author or to the list itself, but
1923 rather to the list manager (which is less annoying).
1925 In multidrop mode, destination headers are processed as follows:
1926 First, fetchmail looks for the Received: header (or whichever one is
1927 specified by the 'envelope' option) to determine the local
1928 recipient address. If the mail is addressed to more than one recipient,
1929 the Received line won't contain any information regarding recipient addresses.
1931 Then fetchmail looks for the Resent-To:, Resent-Cc:, and Resent-Bcc:
1932 lines. If they exist, they should contain the final recipients and
1933 have precedence over their To:/Cc:/Bcc: counterparts. If the Resent-*
1934 lines don't exist, the To:, Cc:, Bcc: and Apparently-To: lines are
1935 looked for. (The presence of a Resent-To: is taken to imply that the
1936 person referred by the To: address has already received the original
1939 .SH CONFIGURATION EXAMPLES
1940 Note that although there are password declarations in a good many
1941 of the examples below, this is mainly for illustrative purposes.
1942 We recommend stashing account/password pairs in your $HOME/.netrc
1943 file, where they can be used not just by fetchmail but by ftp(1) and
1949 poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
1955 poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
1958 Or, using some abbreviations:
1961 poll pop.provider.net proto pop3 user "jsmith" password "secret1"
1964 Multiple servers may be listed:
1967 poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
1968 poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
1971 Here's a version of those two with more whitespace and some noise words:
1974 poll pop.provider.net proto pop3
1975 user "jsmith", with password secret1, is "jsmith" here;
1976 poll other.provider.net proto pop2:
1977 user "John.Smith", with password "My^Hat", is "John.Smith" here;
1980 This version is much easier to read and doesn't cost significantly
1981 more (parsing is done only once, at startup time).
1984 If you need to include whitespace in a parameter string, enclose the
1985 string in double quotes. Thus:
1988 poll mail.provider.net with proto pop3:
1989 user "jsmith" there has password "u can't krak this"
1990 is jws here and wants mda "/bin/mail"
1993 You may have an initial server description headed by the keyword
1994 \&'defaults' instead of 'poll' followed by a name. Such a record
1995 is interpreted as defaults for all queries to use. It may be overwritten
1996 by individual server descriptions. So, you could write:
2001 poll pop.provider.net
2003 poll mail.provider.net
2004 user "jjsmith" there has password "secret2"
2007 It's possible to specify more than one user per server (this is only
2008 likely to be useful when running fetchmail in daemon mode as root).
2009 The 'user' keyword leads off a user description, and every user specification
2010 in a multi-user entry must include it. Here's an example:
2013 poll pop.provider.net proto pop3 port 3111
2014 user "jsmith" with pass "secret1" is "smith" here
2015 user jones with pass "secret2" is "jjones" here keep
2018 This associates the local username 'smith' with the pop.provider.net
2019 username 'jsmith' and the local username 'jjones' with the
2020 pop.provider.net username 'jones'. Mail for 'jones' is kept on the
2021 server after download.
2023 Here's what a simple retrieval configuration for a multi-drop mailbox
2027 poll pop.provider.net:
2028 user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
2031 This says that the mailbox of account 'maildrop' on the server is a
2032 multi-drop box, and that messages in it should be parsed for the
2033 server user names 'golux', 'hurkle', and 'snark'. It further
2034 specifies that 'golux' and 'snark' have the same name on the
2035 client as on the server, but mail for server user 'hurkle' should be
2036 delivered to client user 'happy'.
2038 Here's an example of another kind of multidrop connection:
2041 poll pop.provider.net localdomains loonytoons.org toons.org:
2042 user maildrop with pass secret1 to * here
2045 This also says that the mailbox of account 'maildrop' on the server is
2046 a multi-drop box. It tells fetchmail that any address in the
2047 loonytoons.org or toons.org domains (including sub-domain addresses like
2048 \&'joe@daffy.loonytoons.org') should be passed through to the local SMTP
2049 listener without modification. Be careful of mail loops if you do this!
2051 Here's an example configuration using ssh and the plugin option. The
2052 queries are made directly on the stdin and stdout of imapd via ssh.
2053 Note that in this setup, IMAP authentication can be skipped.
2056 poll mailhost.net with proto imap:
2057 plugin "ssh %h /usr/sbin/imapd" auth ssh;
2058 user esr is esr here
2061 .SH THE USE AND ABUSE OF MULTIDROP MAILBOXES
2062 Use the multiple-local-recipients feature with caution -- it can bite.
2063 All multidrop features are ineffective in ETRN and ODMR modes.
2065 Also, note that in multidrop mode duplicate mails are suppressed. A
2066 piece of mail is considered duplicate if it has the same message-ID as
2067 the message immediately preceding and more than one addressee. Such
2068 runs of messages may be generated when copies of a message addressed
2069 to multiple users are delivered to a multidrop box.
2071 .SS Header vs. Envelope addresses
2072 The fundamental problem is that by having your mailserver toss several
2073 peoples' mail in a single maildrop box, you may have thrown away
2074 potentially vital information about who each piece of mail was
2075 actually addressed to (the 'envelope address', as opposed to the
2076 header addresses in the RFC822 To/Cc headers - the Bcc is not available
2077 at the receiving end). This 'envelope address' is the address you need
2078 in order to reroute mail properly.
2082 can deduce the envelope address. If the mailserver MTA is
2084 and the item of mail had just one recipient, the MTA will have written
2085 a 'by/for' clause that gives the envelope addressee into its Received
2086 header. But this doesn't work reliably for other MTAs, nor if there is
2087 more than one recipient. By default, \fIfetchmail\fR looks for
2088 envelope addresses in these lines; you can restore this default with
2089 -E "Received" or \&'envelope Received'.
2091 .B As a better alternative,
2092 some SMTP listeners and/or mail servers insert a header
2093 in each message containing a copy of the envelope addresses. This
2094 header (when it exists) is often 'X-Original-To', 'Delivered-To' or
2095 'X-Envelope-To'. Fetchmail's assumption about this can be changed with
2096 the -E or 'envelope' option. Note that writing an envelope header of
2097 this kind exposes the names of recipients (including blind-copy
2098 recipients) to all receivers of the messages, so the upstream must store
2099 one copy of the message per recipient to avoid becoming a privacy problem.
2101 Postfix, since version 2.0, writes an X-Original-To: header which
2102 contains a copy of the envelope as it was received.
2104 Qmail and Postfix generally write a 'Delivered-To' header upon
2105 delivering the message to the mail spool and use it to avoid mail loops.
2106 Qmail virtual domains however will prefix the user name with a string
2107 that normally matches the user's domain. To remove this prefix you can
2108 use the -Q or 'qvirtual' option.
2110 Sometimes, unfortunately, neither of these methods works. That is the
2111 point when you should contact your ISP and ask them to provide such an
2112 envelope header, and you should not use multidrop in this situation.
2113 When they all fail, fetchmail must fall back on the contents of To/Cc
2114 headers (Bcc headers are not available - see below) to try to determine
2115 recipient addressees -- and these are unreliable.
2116 In particular, mailing-list software often ships mail with only
2117 the list broadcast address in the To header.
2119 .B Note that a future version of fetchmail may remove To/Cc parsing!
2123 cannot deduce a recipient address that is local, and the intended
2124 recipient address was anyone other than fetchmail's invoking user,
2125 .B mail will get lost.
2126 This is what makes the multidrop feature risky without proper envelope
2129 A related problem is that when you blind-copy a mail message, the Bcc
2130 information is carried \fIonly\fR as envelope address (it's removed from
2131 the headers by the sending mail server, so fetchmail can see it only if
2132 there is an X-Envelope-To header). Thus, blind-copying to someone who
2133 gets mail over a fetchmail multidrop link will fail unless the the
2134 mailserver host routinely writes X-Envelope-To or an equivalent header
2135 into messages in your maildrop.
2137 \fBIn conclusion, mailing lists and Bcc'd mail can only work if the
2138 server you're fetching from (1) stores one copy of the message per
2139 recipient in \fBIyour\fP domain and (2) records the envelope
2140 information in a special header (X-Original-To, Delivered-To,
2143 .SS Good Ways To Use Multidrop Mailboxes
2144 Multiple local names can be used to administer a mailing list from the
2145 client side of a \fIfetchmail\fR collection. Suppose your name is
2146 \&'esr', and you want to both pick up your own mail and maintain a mailing
2147 list called (say) "fetchmail-friends", and you want to keep the alias
2148 list on your client machine.
2150 On your server, you can alias \&'fetchmail-friends' to 'esr'; then, in
2151 your \fI.fetchmailrc\fR, declare \&'to esr fetchmail-friends here'.
2152 Then, when mail including 'fetchmail-friends' as a local address
2153 gets fetched, the list name will be appended to the list of
2154 recipients your SMTP listener sees. Therefore it will undergo alias
2155 expansion locally. Be sure to include 'esr' in the local alias
2156 expansion of fetchmail-friends, or you'll never see mail sent only to
2157 the list. Also be sure that your listener has the "me-too" option set
2158 (sendmail's -oXm command-line option or OXm declaration) so your name
2159 isn't removed from alias expansions in messages you send.
2161 This trick is not without its problems, however. You'll begin to see
2162 this when a message comes in that is addressed only to a mailing list
2163 you do \fInot\fR have declared as a local name. Each such message
2164 will feature an 'X-Fetchmail-Warning' header which is generated
2165 because fetchmail cannot find a valid local name in the recipient
2166 addresses. Such messages default (as was described above) to being
2167 sent to the local user running
2169 but the program has no way to know that that's actually the right thing.
2171 .SS Bad Ways To Abuse Multidrop Mailboxes
2172 Multidrop mailboxes and
2174 serving multiple users in daemon mode do not mix. The problem, again, is
2175 mail from mailing lists, which typically does not have an individual
2176 recipient address on it. Unless
2178 can deduce an envelope address, such mail will only go to the account
2179 running fetchmail (probably root). Also, blind-copied users are very
2180 likely never to see their mail at all.
2182 If you're tempted to use
2184 to retrieve mail for multiple users from a single mail drop via POP or
2185 IMAP, think again (and reread the section on header and envelope
2186 addresses above). It would be smarter to just let the mail sit in the
2187 mailserver's queue and use fetchmail's ETRN or ODMR modes to trigger
2188 SMTP sends periodically (of course, this means you have to poll more
2189 frequently than the mailserver's expiry period). If you can't arrange
2190 this, try setting up a UUCP feed.
2192 If you absolutely \fImust\fR use multidrop for this purpose, make sure
2193 your mailserver writes an envelope-address header that fetchmail can
2194 see. Otherwise you \fIwill\fR lose mail and it \fIwill\fR come back
2197 .SS Speeding Up Multidrop Checking
2198 Normally, when multiple users are declared
2200 extracts recipient addresses as described above and checks each host
2201 part with DNS to see if it's an alias of the mailserver. If so, the
2202 name mappings described in the "to ... here" declaration are done and
2203 the mail locally delivered.
2205 This is a convenient but also slow method. To speed
2206 it up, pre-declare mailserver aliases with 'aka'; these are checked
2207 before DNS lookups are done. If you're certain your aka list contains
2209 DNS aliases of the mailserver (and all MX names pointing at it - note
2210 this may change in a future version)
2211 you can declare 'no dns' to suppress DNS lookups entirely and
2212 \fIonly\fR match against the aka list.
2215 To facilitate the use of
2217 in shell scripts, an exit code is returned to give an indication
2218 of what occurred during a given connection.
2220 The exit codes returned by
2224 One or more messages were successfully retrieved (or, if the -c option
2225 was selected, were found waiting but not retrieved).
2227 There was no mail awaiting retrieval. (There may have been old mail still
2228 on the server but not selected for retrieval.)
2230 An error was encountered when attempting to open a socket to retrieve
2231 mail. If you don't know what a socket is, don't worry about it --
2232 just treat this as an 'unrecoverable error'. This error can also be
2233 because a protocol fetchmail wants to use is not listed in /etc/services.
2235 The user authentication step failed. This usually means that a bad
2236 user-id, password, or APOP id was specified. Or it may mean that you
2237 tried to run fetchmail under circumstances where it did not have
2238 standard input attached to a terminal and could not prompt for a
2241 Some sort of fatal protocol error was detected.
2243 There was a syntax error in the arguments to
2246 The run control file had bad permissions.
2248 There was an error condition reported by the server. Can also
2251 timed out while waiting for the server.
2253 Client-side exclusion error. This means
2255 either found another copy of itself already running, or failed in such
2256 a way that it isn't sure whether another copy is running.
2258 The user authentication step failed because the server responded "lock
2259 busy". Try again after a brief pause! This error is not implemented
2260 for all protocols, nor for all servers. If not implemented for your
2261 server, "3" will be returned instead, see above. May be returned when
2262 talking to qpopper or other servers that can respond with "lock busy"
2263 or some similar text containing the word "lock".
2267 run failed while trying to do an SMTP port open or transaction.
2269 Fatal DNS error. Fetchmail encountered an error while performing
2270 a DNS lookup at startup and could not proceed.
2272 BSMTP batch file could not be opened.
2274 Poll terminated by a fetch limit (see the --fetchlimit option).
2276 Server busy indication.
2278 Server timed out during an IMAP IDLE.
2280 Internal error. You should see a message on standard error with
2285 queries more than one host, return status is 0 if \fIany\fR query
2286 successfully retrieved mail. Otherwise the returned error status is
2287 that of the last host queried.
2292 default run control file
2295 default location of file associating hosts with last message IDs seen
2296 (used only with newer RFC1939-compliant POP3 servers supporting the
2300 lock file to help prevent concurrent runs (non-root mode).
2303 your FTP run control file, which (if present) will be searched for
2304 passwords as a last resort before prompting for one interactively.
2306 /var/run/fetchmail.pid
2307 lock file to help prevent concurrent runs (root mode, Linux systems).
2310 lock file to help prevent concurrent runs (root mode, systems without /var/run).
2313 If the FETCHMAILUSER variable is set, it is used as the name of the
2314 calling user (default local name) for purposes such as mailing error
2315 notifications. Otherwise, if either the LOGNAME or USER variable is
2316 correctly set (e.g. the corresponding UID matches the session user ID)
2317 then that name is used as the default local name. Otherwise
2318 \fBgetpwuid\fR(3) must be able to retrieve a password entry for the
2319 session ID (this elaborate logic is designed to handle the case of
2320 multiple names per userid gracefully).
2322 If the environment variable FETCHMAILHOME is set to a valid and
2323 existing directory name, the .fetchmailrc and .fetchids and
2324 \&.fetchmail.pid files are put there instead of in the invoking user's
2325 home directory (and lose the leading dots on their names). The
2326 \&.netrc file is looked for in the the invoking user's home directory
2327 regardless of FETCHMAILHOME's setting.
2329 If the HOME_ETC variable is set, file $HOME_ETC/.fetchmailrc is used
2330 instead of ~/.fetchmailrc.
2335 daemon is running as root, SIGHUP wakes it up from its sleep phase and
2336 forces a poll of all non-skipped servers (this is in accordance with
2337 the usual conventions for system daemons).
2341 is running in daemon mode as non-root, use SIGUSR1 to wake it (this is
2342 so SIGHUP due to logout can retain the default action of killing it).
2346 in foreground while a background fetchmail is running will do
2347 whichever of these is appropriate to wake it up.
2349 .SH BUGS AND KNOWN PROBLEMS
2351 The assumptions that the DNS and in particular the checkalias options
2352 make are not often sustainable. For instance, it has become uncommon for
2353 an MX server to be a POP3 or IMAP server at the same time. Therefore the
2354 MX lookups may go away in a future release.
2356 The mda and plugin options interact badly. In order to collect error
2357 status from the MDA, fetchmail has to change its normal signal
2358 handling so that dead plugin processes don't get reaped until the end
2359 of the poll cycle. This can cause resource starvation if too many
2360 zombies accumulate. So either don't deliver to a MDA using plugins or
2361 risk being overrun by an army of undead.
2363 The --interface option does not support IPv6 and it is doubtful if it
2364 ever will, since there is no portable way to query interface IPv6
2367 The RFC822 address parser used in multidrop mode chokes on some
2368 @-addresses that are technically legal but bizarre. Strange uses of
2369 quoting and embedded comments are likely to confuse it.
2371 In a message with multiple envelope headers, only the last one
2372 processed will be visible to fetchmail. To get around this, use a
2373 mailserver-side filter that consolidates the contents of all envelope
2374 headers into a single one (procmail, mailagent, or maildrop can be
2375 programmed to do this fairly easily).
2377 Use of some of these protocols requires that the program send
2378 unencrypted passwords over the TCP/IP connection to the mailserver.
2379 This creates a risk that name/password pairs might be snaffled with a
2380 packet sniffer or more sophisticated monitoring software. Under Linux
2381 and FreeBSD, the --interface option can be used to restrict polling to
2382 availability of a specific interface device with a specific local or
2383 remote IP address, but snooping is still possible if (a) either host
2384 has a network device that can be opened in promiscuous mode, or (b)
2385 the intervening network link can be tapped. We recommend the use of
2387 tunnelling to not only shroud your passwords but encrypt the entire
2390 Use of the %F or %T escapes in an mda option could open a security
2391 hole, because they pass text manipulable by an attacker to a shell
2392 command. Potential shell characters are replaced by '_' before
2393 execution. The hole is further reduced by the fact that fetchmail
2394 temporarily discards any suid privileges it may have while running the
2395 MDA. For maximum safety, however, don't use an mda command containing
2396 %F or %T when fetchmail is run from the root account itself.
2398 Fetchmail's method of sending bounces due to errors or spam-blocking and
2399 spam bounces requires that port 25 of localhost be available for sending
2404 while a background instance is running and break the syntax, the
2405 background instance will die silently. Unfortunately, it can't
2406 die noisily because we don't yet know whether syslog should be enabled.
2407 On some systems, fetchmail dies quietly even if there is no syntax
2408 error; this seems to have something to do with buggy terminal ioctl
2411 The -f - option (reading a configuration from stdin) is incompatible
2412 with the plugin option.
2414 The 'principal' option only handles Kerberos IV, not V.
2416 The --smtphost defaults may not be adequate for your system. In doubt,
2417 specify this option explicitly to set your forward destination.
2419 Send comments, bug reports, gripes, and the like to the
2420 fetchmail-devel list <fetchmail-devel@lists.berlios.de>. An HTML FAQ is
2421 available at the fetchmail home page; surf to
2422 http://fetchmail.berlios.de/ or do a WWW search for pages with
2423 \&'fetchmail' in their titles.
2426 Eric S. Raymond <esr@snark.thyrsus.com>. Too many other people to
2427 name here have contributed code and patches.
2428 This program is descended from and replaces
2430 by Carl Harris <ceharris@mal.com>; the internals have become quite different,
2431 but some of its interface design is directly traceable to that
2434 This manual page has been improved by R.\ Hannes Beinert.
2436 Fetchmail is currently maintained by Matthias Andree and Rob Funk.
2439 mutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8), netrc(5)
2440 .SH APPLICABLE STANDARDS
2443 RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC 1983, RFC 1985,
2447 RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
2453 RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC 1939, RFC 1957,
2457 RFC 1460, RFC 1725, RFC 1939.
2466 RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC 2195, RFC 2177,
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