fetchmail(1)fetchmail(1)NAMEfetchmail - fetch mail from a POP, IMAP, ETRN, or ODMR-
capable server
SYNOPSISfetchmail [option...] [mailserver...]
fetchmailconf
DESCRIPTIONfetchmail is a mail-retrieval and forwarding utility; it
fetches mail from remote mailservers and forwards it to
your local (client) machine's delivery system. You can
then handle the retrieved mail using normal mail user
agents such as mutt(1), elm(1) or Mail(1). The fetchmail
utility can be run in a daemon mode to repeatedly poll one
or more systems at a specified interval.
The fetchmail program can gather mail from servers sup
porting any of the common mail-retrieval protocols: POP2,
POP3, IMAP2bis, IMAP4, and IMAPrev1. It can also use the
ESMTP ETRN extension and ODMR. (The RFCs describing all
these protocols are listed at the end of this manual
page.)
While fetchmail is primarily intended to be used over on-
demand TCP/IP links (such as SLIP or PPP connections), it
may also be useful as a message transfer agent for sites
which refuse for security reasons to permit (sender-initi
ated) SMTP transactions with sendmail.
As each message is retrieved fetchmail normally delivers
it via SMTP to port 25 on the machine it is running on
(localhost), just as though it were being passed in over a
normal TCP/IP link. The mail will then be delivered
locally via your system's MDA (Mail Delivery Agent, usu
ally sendmail(8) but your system may use a different one
such as smail, mmdf, exim, or qmail). All the delivery-
control mechanisms (such as .forward files) normally
available through your system MDA and local delivery
agents will therefore work.
If no port 25 listener is available, but your fetchmail
configuration was told about a reliable local MDA, it will
use that MDA for local delivery instead. At build time,
fetchmail normally looks for executable procmail(1) and
sendmail(1) binaries.
If the program fetchmailconf is available, it will assist
you in setting up and editing a fetchmailrc configuration.
It runs under X and requires that the language Python and
the Tk toolkit be present on your system. If you are
first setting up fetchmail for single-user mode, it is
recommended that you use Novice mode. Expert mode pro
vides complete control of fetchmail configuration, includ
ing the multidrop features. In either case, the `Auto
probe' button will tell you the most capable protocol a
given mailserver supports, and warn you of potential prob
lems with that server.
GENERAL OPERATION
The behavior of fetchmail is controlled by command-line
options and a run control file, ~/.fetchmailrc, the syntax
of which we describe in a later section (this file is what
the fetchmailconf program edits). Command-line options
override ~/.fetchmailrc declarations.
Each server name that you specify following the options on
the command line will be queried. If you don't specify
any servers on the command line, each `poll' entry in your
~/.fetchmailrc file will be queried.
To facilitate the use of fetchmail in scripts and
pipelines, it returns an appropriate exit code upon termi
nation -- see EXIT CODES below.
The following options modify the behavior of fetchmail.
It is seldom necessary to specify any of these once you
have a working .fetchmailrc file set up.
Almost all options have a corresponding keyword which can
be used to declare them in a .fetchmailrc file.
Some special options are not covered here, but are docu
mented instead in sections on AUTHENTICATION and DAEMON
MODE which follow.
General Options
-V | --version
Displays the version information for your copy of
fetchmail. No mail fetch is performed. Instead,
for each server specified, all the option informa
tion that would be computed if fetchmail were con
necting to that server is displayed. Any non-
printables in passwords or other string names are
shown as backslashed C-like escape sequences. This
option is useful for verifying that your options
are set the way you want them.
-c | --check
Return a status code to indicate whether there is
mail waiting, without actually fetching or deleting
mail (see EXIT CODES below). This option turns off
daemon mode (in which it would be useless). It
doesn't play well with queries to multiple sites,
and doesn't work with ETRN or ODMR. It will return
a false positive if you leave read but undeleted
mail in your server mailbox and your fetch protocol
can't tell kept messages from new ones. This means
it will work with IMAP, not work with POP2, and may
occasionally flake out under POP3.
-s | --silent
Silent mode. Suppresses all progress/status mes
sages that are normally echoed to standard error
during a fetch (but does not suppress actual error
messages). The --verbose option overrides this.
-v | --verbose
Verbose mode. All control messages passed between
fetchmail and the mailserver are echoed to stdout.
Overrides --silent. Doubling this option (-v -v)
causes extra diagnostic information to be printed.
Disposal Options
-a | --all
(Keyword: fetchall) Retrieve both old (seen) and
new messages from the mailserver. The default is
to fetch only messages the server has not marked
seen. Under POP3, this option also forces the use
of RETR rather than TOP. Note that POP2 retrieval
behaves as though --all is always on (see RETRIEVAL
FAILURE MODES below) and this option does not work
with ETRN or ODMR.
-k | --keep
(Keyword: keep) Keep retrieved messages on the
remote mailserver. Normally, messages are deleted
from the folder on the mailserver after they have
been retrieved. Specifying the keep option causes
retrieved messages to remain in your folder on the
mailserver. This option does not work with ETRN or
ODMR.
-K | --nokeep
(Keyword: nokeep) Delete retrieved messages from
the remote mailserver. This option forces
retrieved mail to be deleted. It may be useful if
you have specified a default of keep in your
.fetchmailrc. This option is forced on with ETRN
and ODMR.
-F | --flush
POP3/IMAP only. Delete old (previously retrieved)
messages from the mailserver before retrieving new
messages. This option does not work with ETRN or
ODMR. Warning: if your local MTA hangs and fetch
mail is aborted, the next time you run fetchmail,
it will delete mail that was never delivered to
you. What you probably want is the default set
ting: if you don't specify `-k', then fetchmail
will automatically delete messages after successful
delivery.
Protocol and Query Options
-p <proto> | --protocol <proto>
(Keyword: proto[col]) Specify the protocol to use
when communicating with the remote mailserver. If
no protocol is specified, the default is AUTO.
proto may be one of the following:
AUTO Tries IMAP, POP3, and POP2 (skipping any of
these for which support has not been com
piled in).
POP2 Post Office Protocol 2
POP3 Post Office Protocol 3
APOP Use POP3 with old-fashioned MD5-challenge
authentication.
RPOP Use POP3 with RPOP authentication.
KPOP Use POP3 with Kerberos V4 authentication on
port 1109.
SDPS Use POP3 with Demon Internet's SDPS exten
sions.
IMAP IMAP2bis, IMAP4, or IMAP4rev1 (fetchmail
autodetects their capabilities).
ETRN Use the ESMTP ETRN option.
ODMR Use the the On-Demand Mail Relay ESMTP pro
file.
All these alternatives work in basically the same way
(communicating with standard server daemons to fetch mail
already delivered to a mailbox on the server) except ETRN
and ODMR. The ETRN mode allows you to ask a compliant
ESMTP server (such as BSD sendmail at release 8.8.0 or
higher) to immediately open a sender-SMTP connection to
your client machine and begin forwarding any items
addressed to your client machine in the server's queue of
undelivered mail. The ODMR mode requires an ODMR-capable
server and works similarly to ETRN, except that it does
not require the client machine to have a static DNS.
-U | --uidl
(Keyword: uidl) Force UIDL use (effective only with
POP3). Force client-side tracking of `newness' of
messages (UIDL stands for ``unique ID listing'' and
is described in RFC1725). Use with `keep' to use a
mailbox as a baby news drop for a group of users.
The fact that seen messages are skipped is logged,
unless error logging is done through syslog while
running in daemon mode.
-P <portnumber> | --port <portnumber>
(Keyword: port) The port option permits you to
specify a TCP/IP port to connect on. This option
will seldom be necessary as all the supported pro
tocols have well-established default port numbers.
--principal <principal>
(Keyword: principal) The principal option permits
you to specify a service principal for mutual
authentication. This is applicable to POP3 or IMAP
with Kerberos authentication.
-t <seconds> | --timeout <seconds>
(Keyword: timeout) The timeout option allows you to
set a server-nonresponse timeout in seconds. If a
mailserver does not send a greeting message or
respond to commands for the given number of sec
onds, fetchmail will hang up on it. Without such a
timeout fetchmail might hang up indefinitely trying
to fetch mail from a down host. This would be par
ticularly annoying for a fetchmail running in back
ground. There is a default timeout which fetchmail-V will report. If a given connection receives too
many timeouts in succession, fetchmail will con
sider it wedged and stop retrying, the calling user
will be notified by email if this happens.
--plugin <command>
(Keyword: plugin) The plugin option allows you to
use an external program to establish the TCP con
nection. This is useful if you want to use socks,
SSL, ssh, or need some special firewalling setup.
The program will be looked up in $PATH and can
optionally be passed the hostname and port as argu
ments using "%h" and "%p" respectively (note that
the interpolation logic is rather primitive, and
these token must be bounded by whitespace or
beginning of string or end of string). Fetchmail
will write to the plugin's stdin and read from the
plugin's stdout.
--plugout <command>
(Keyword: plugout) Identical to the plugin option
above, but this one is used for the SMTP connec
tions (which will probably not need it, so it has
been separated from plugin).
-r <name> | --folder <name>
(Keyword: folder[s]) Causes a specified non-default
mail folder on the mailserver (or comma-separated
list of folders) to be retrieved. The syntax of
the folder name is server-dependent. This option
is not available under POP3, ETRN, or ODMR.
--tracepolls
(Keyword: tracepolls) Tell fetchail to poll trace
information in the form `polling %s account %s' to
the Received line it generates, where the %s parts
are replaced by the user's remote name and the poll
label (the Received header also normally includes
the server's truename). This can be used to
facilate mail filtering based on the account it is
being received from.
--ssl (Keyword: ssl) Causes the connection to the mail
server to be encrypted via SSL. Connect to the
server using the specified base protocol over a
connection secured by SSL. SSL support must be
present at the server. If no port is specified,
the connection is attempted to the well known port
of the SSL version of the base protocol. This is
generally a different port than the port used by
the base protocol. For IMAP, this is port 143 for
the clear protocol and port 993 for the SSL secured
protocol.
--sslcert <name>
(Keyword: sslcert) Specifies the file name of the
client side public SSL certificate. Some SSL
encrypted servers may require client side keys and
certificates for authentication. In most cases,
this is optional. This specifies the location of
the public key certificate to be presented to the
server at the time the SSL session is established.
It is not required (but may be provided) if the
server does not require it. Some servers may
require it, some servers may request it but not
require it, and some servers may not request it at
all. It may be the same file as the private key
(combined key and certificate file) but this is not
recommended.
--sslkey <name>
(Keyword: sslkey) Specifies the file name of the
client side private SSL key. Some SSL encrypted
servers may require client side keys and certifi
cates for authentication. In most cases, this is
optional. This specifies the location of the pri
vate key used to sign transactions with the server
at the time the SSL session is established. It is
not required (but may be provided) if the server
does not require it. Some servers may require it,
some servers may request it but not require it, and
some servers may not request it at all. It may be
the same file as the public key (combined key and
certificate file) but this is not recommended. If
a password is required to unlock the key, it will
be prompted for at the time just prior to estab
lishing the session to the server. This can cause
some complications in daemon mode.
--sslproto <name>
(Keyword: sslproto) Forces an ssl protocol. Possi
ble values are `ssl2', `ssl3' and `tls1'. Try this
if the default handshake does not work for your
server.
--sslcertck
(Keyword: sslcertck) Causes fetchmail to strictly
check the server certificate against a set of local
trusted certificates (see the sslcertpath option).
If the server certificate is not signed by one of
the trusted ones (directly or indirectly), the SSL
connection will fail. This checking should prevent
man-in-the-middle attacks against the SSL connec
tion. Note that CRLs are seemingly not currently
supported by OpenSSL in certificate verification!
Your system clock should be reasonably accurate
when using this option!
--sslcertpath <directory>
(Keyword: sslcertpath) Sets the directory fetchmail
uses to look up local certificates. The default is
your OpenSSL default one. The directory must be
hashed as OpenSSL expects it - every time you add
or modify a certificate in the directory, you need
to use the c_rehash tool (which comes with OpenSSL
in the tools/ subdirectory).
--sslfingerprint
(Keyword: sslfingerprint) Specify the fingerprint
of the server key (an MD5 hash of the key) in hex
adecimal notation with colons separating groups of
two digits. The letter hex digits must be in upper
case. This is the default format OpenSSL uses, and
the one fetchmail uses to report the fingerprint
when an SSL connection is established. When this is
specified, fetchmail will compare the server key
fingerprint with the given one, and the connection
will fail if they do not match. This can be used to
prevent man-in-the-middle attacks.
Delivery Control Options
-S <hosts> | --smtphost <hosts>
(Keyword: smtp[host]) Specify a hunt list of hosts
to forward mail to (one or more hostnames, comma-
separated). Hosts are tried in list order; the
first one that is up becomes the forwarding target
for the current run. Normally, `localhost' is
added to the end of the list as an invisible
default. However, when using Kerberos authentica
tion, the FQDN of the machine running fetchmail is
added to the end of the list as an invisible
default. Each hostname may have a port number fol
lowing the host name. The port number is separated
from the host name by a slash; the default port is
25 (or ``smtp'' under IPv6). If you specify an
absolute pathname (beginning with a /), it will be
interpreted as the name of a UNIX socket accepting
LMTP connections (such as is supported by the Cyrus
IMAP daemon) Example:
--smtphost server1,server2/2525,server3,/var/imap/socket/lmtp
This option can be used with ODMR, and will make
fetchmail a relay between the ODMR server and SMTP
or LMTP receiver.
--fetchdomains <hosts>
(Keyword: fetchdomains) In ETRN or ODMR mode, this
option specifies the list of domains the server
should ship mail for once the connection is turned
around. The default is the FQDN of the machine
running fetchmail.
-D <domain> | --smtpaddress <domain>
(Keyword: smtpaddress) Specify the domain to be
appended to addresses in RCPT TO lines shipped to
SMTP. The name of the SMTP server (as specified by
--smtphost, or defaulted to "localhost") is used
when this is not specified.
--smtpname <user@domain>
(Keyword: smtpname) Specify the domain and user to
be put in RCPT TO lines shipped to SMTP. The
default user is the current local user.
-Z <nnn> | --antispam <nnn[, nnn]...>
(Keyword: antispam) Specifies the list of numeric
SMTP errors that are to be interpreted as a spam-
block response from the listener. A value of -1
disables this option. For the command-line option,
the list values should be comma-separated.
-m <command> | --mda <command>
(Keyword: mda) You can force mail to be passed to
an MDA directly (rather than forwarded to port 25)
with the --mda or -m option. To avoid losing mail,
use this option only with MDAs like procmail or
sendmail that return a nonzero status on disk-full
and other resource-exhaustion errors; the nonzero
status tells fetchmail that delivery failed and
prevents the message from being deleted off the
server. If fetchmail is running as root, it sets
its userid to that of the target user while deliv
ering mail through an MDA. Some possible MDAs are
"/usr/sbin/sendmail -i-oem-f %F %T",
"/usr/bin/deliver" and "/usr/bin/procmail -d %T"
(but the latter is usually redundant as it's what
SMTP listeners normally forward to). Local deliv
ery addresses will be inserted into the MDA command
wherever you place a %T; the mail message's From
address will be inserted where you place an %F. Do
not use an MDA invocation like "sendmail -i -oem
-t" that dispatches on the contents of To/Cc/Bcc,
it will create mail loops and bring the just wrath
of many postmasters down upon your head.
--lmtp (Keyword: lmtp) Cause delivery via LMTP (Local Mail
Transfer Protocol). A service port must be explic
itly specified (with a slash suffix) on each host
in the smtphost hunt list if this option is
selected; the default port 25 will (in accordance
with RFC 2033) not be accepted.
--bsmtp <filename>
(keyword: bsmtp) Append fetched mail to a BSMTP
file. This simply contains the SMTP commands that
would normally be generated by fetchmail when pass
ing mail to an SMTP listener daemon. An argument
of `-' causes the mail to be written to standard
output. Note that fetchmail's reconstruction of
MAIL FROM and RCPT TO lines is not guaranteed cor
rect; the caveats discussed under THE USE AND ABUSE
OF MULTIDROP MAILBOXES below apply.
Resource Limit Control Options
-l <maxbytes> | --limit <maxbytes>
(Keyword: limit) Takes a maximum octet size argu
ment. Messages larger than this size will not be
fetched and will be left on the server (in fore
ground sessions, the progress messages will note
that they are "oversized"). If the fetch protocol
permits (in particular, under IMAP or POP3 without
the fetchall option) the message will not be marked
seen An explicit --limit of 0 overrides any limits
set in your run control file. This option is
intended for those needing to strictly control
fetch time due to expensive and variable phone
rates. In daemon mode, oversize notifications are
mailed to the calling user (see the --warnings
option). This option does not work with ETRN or
ODMR.
-w <interval> | --warnings <interval>
(Keyword: warnings) Takes an interval in seconds.
When you call fetchmail with a `limit' option in
daemon mode, this controls the interval at which
warnings about oversized messages are mailed to the
calling user (or the user specified by the `post
master' option). One such notification is always
mailed at the end of the the first poll that the
oversized message is detected. Thereafter, renoti
fication is suppressed until after the warning
interval elapses (it will take place at the end of
the first following poll).
-b <count> | --batchlimit <count>
(Keyword: batchlimit) Specify the maximum number of
messages that will be shipped to an SMTP listener
before the connection is deliberately torn down and
rebuilt (defaults to 0, meaning no limit). An
explicit --batchlimit of 0 overrides any limits set
in your run control file. While sendmail(8) nor
mally initiates delivery of a message immediately
after receiving the message terminator, some SMTP
listeners are not so prompt. MTAs like smail(8)
may wait till the delivery socket is shut down to
deliver. This may produce annoying delays when
fetchmail is processing very large batches. Set
ting the batch limit to some nonzero size will pre
vent these delays. This option does not work with
ETRN or ODMR.
-B <number> | --fetchlimit <number>
(Keyword: fetchlimit) Limit the number of messages
accepted from a given server in a single poll. By
default there is no limit. An explicit --fetchlimit
of 0 overrides any limits set in your run control
file. This option does not work with ETRN or ODMR.
-e <count> | --expunge <count>
(keyword: expunge) Arrange for deletions to be made
final after a given number of messages. Under POP2
or POP3, fetchmail cannot make deletions final
without sending QUIT and ending the session -- with
this option on, fetchmail will break a long mail
retrieval session into multiple subsessions, send
ing QUIT after each sub-session. This is a good
defense against line drops on POP3 servers that do
not do the equivalent of a QUIT on hangup. Under
IMAP, fetchmail normally issues an EXPUNGE command
after each deletion in order to force the deletion
to be done immediately. This is safest when your
connection to the server is flaky and expensive, as
it avoids resending duplicate mail after a line
hit. However, on large mailboxes the overhead of
re-indexing after every message can slam the server
pretty hard, so if your connection is reliable it
is good to do expunges less frequently. Also note
that some servers enforce a delay of a few seconds
after each quit, so fetchmail may not be able to
get back in immediately after an expunge -- you may
see "lock busy" errors if this happens. If you
specify this option to an integer N, it tells
fetchmail to only issue expunges on every Nth
delete. An argument of zero suppresses expunges
entirely (so no expunges at all will be done until
the end of run). This option does not work with
ETRN or ODMR.
Authentication Options
-u <name> | --username <name>
(Keyword: user[name]) Specifies the user identifi
cation to be used when logging in to the
mailserver. The appropriate user identification is
both server and user-dependent. The default is
your login name on the client machine that is run
ning fetchmail. See USER AUTHENTICATION below for
a complete description.
-I <specification> | --interface <specification>
(Keyword: interface) Require that a specific inter
face device be up and have a specific local or
remote IP address (or range) before polling. Fre
quently fetchmail is used over a transient point-
to-point TCP/IP link established directly to a
mailserver via SLIP or PPP. That is a relatively
secure channel. But when other TCP/IP routes to
the mailserver exist (e.g. when the link is con
nected to an alternate ISP), your username and
password may be vulnerable to snooping (especially
when daemon mode automatically polls for mail,
shipping a clear password over the net at pre
dictable intervals). The --interface option may be
used to prevent this. When the specified link is
not up or is not connected to a matching IP
address, polling will be skipped. The format is:
interface/iii.iii.iii.iii/mmm.mmm.mmm.mmm
The field before the first slash is the interface
name (i.e. sl0, ppp0 etc.). The field before the
second slash is the acceptable IP address. The
field after the second slash is a mask which speci
fies a range of IP addresses to accept. If no mask
is present 255.255.255.255 is assumed (i.e. an
exact match). This option is currently only sup
ported under Linux and FreeBSD. Please see the mon
itor section for below for FreeBSD specific infor
mation.
-M <interface> | --monitor <interface>
(Keyword: monitor) Daemon mode can cause transient
links which are automatically taken down after a
period of inactivity (e.g. PPP links) to remain up
indefinitely. This option identifies a system
TCP/IP interface to be monitored for activity.
After each poll interval, if the link is up but no
other activity has occurred on the link, then the
poll will be skipped. However, when fetchmail is
woken up by a signal, the monitor check is skipped
and the poll goes through unconditionally. This
option is currently only supported under Linux and
FreeBSD. For the monitor and interface options to
work for non root users under FreeBSD, the fetch
mail binary must be installed SGID kmem. This would
be a security hole, but fetchmail runs with the
effective GID set to that of the kmem group only
when interface data is being collected.
--auth <type>
(Keyword: auth[enticate]) This option permits you
to specify an authentication type (see USER AUTHEN
TICATION below for details). The possible values
are any, `password', `kerberos_v5' and `kerberos'
(or, for excruciating exactness, `kerberos_v4'),
gssapi, cram-md5, otp, ntlm, and ssh. When any
(the default) is specified, fetchmail tries first
methods that don't require a password (GSSAPI, KER
BEROS_IV); then it looks for methods that mask your
password (CRAM-MD5, X-OTP, NTLM); and only if the
server doesn't support any of those will it ship
your password en clair. Other values may be used
to force various authentication methods (ssh sup
presses authentication). Any value other than
password, cram-md5, ntlm or otp suppresses fetch
mail's normal inquiry for a password. Specify ssh
when you are using an end-to-end secure connection
such as an ssh tunnel; specify gssapi or ker
beros_v4 if you are using a protocol variant that
employs GSSAPI or K4. Choosing KPOP protocol auto
matically selects Kerberos authentication. This
option does not work with ETRN.
Miscellaneous Options
-f <pathname> | --fetchmailrc <pathname>
Specify a non-default name for the ~/.fetchmailrc
run control file. The pathname argument must be
either "-" (a single dash, meaning to read the con
figuration from standard input) or a filename.
Unless the --version option is also on, a named
file argument must have permissions no more open
than 0600 (u=rw,g=,o=) or else be /dev/null.
-i <pathname> | --idfile <pathname>
(Keyword: idfile) Specify an alternate name for the
.fetchids file used to save POP3 UIDs.
-n | --norewrite
(Keyword: no rewrite) Normally, fetchmail edits
RFC-822 address headers (To, From, Cc, Bcc, and
Reply-To) in fetched mail so that any mail IDs
local to the server are expanded to full addresses
(@ and the mailserver hostname are appended). This
enables replies on the client to get addressed cor
rectly (otherwise your mailer might think they
should be addressed to local users on the client
machine!). This option disables the rewrite.
(This option is provided to pacify people who are
paranoid about having an MTA edit mail headers and
want to know they can prevent it, but it is gener
ally not a good idea to actually turn off rewrite.)
When using ETRN or ODMR, the rewrite option is
ineffective.
-E <line> | --envelope <line>
(Keyword: envelope) This option changes the header
fetchmail assumes will carry a copy of the mail's
envelope address. Normally this is `X-Envelope-To'
but as this header is not standard, practice
varies. See the discussion of multidrop address
handling below. As a special case, `envelope
"Received"' enables parsing of sendmail-style
Received lines. This is the default, and it should
not be necessary unless you have globally disabled
Received parsing with `no envelope' in the .fetch_
mailrc file.
-Q <prefix> | --qvirtual <prefix>
(Keyword: qvirtual) The string prefix assigned to
this option will be removed from the user name
found in the header specified with the envelope
option (before doing multidrop name mapping or
localdomain checking, if either is applicable).
This option is useful if you are using fetchmail to
collect the mail for an entire domain and your ISP
(or your mail redirection provider) is using qmail.
One of the basic features of qmail is the
`Delivered-To:'
message header. Whenever qmail delivers a message
to a local mailbox it puts the username and host
name of the envelope recipient on this line. The
major reason for this is to prevent mail loops. To
set up qmail to batch mail for a disconnected site
the ISP-mailhost will have normally put that site
in its `Virtualhosts' control file so it will add a
prefix to all mail addresses for this site. This
results in mail sent to 'username@userhost.user
dom.dom.com' having a `Delivered-To:' line of the
form:
Delivered-To: mbox-userstr-username@userhost.user
dom.dom.com
The ISP can make the 'mbox-userstr-' prefix any
thing they choose but a string matching the user
host name is likely. By using the option `envelope
Delivered-To:' you can make fetchmail reliably
identify the original envelope recipient, but you
have to strip the `mbox-userstr-' prefix to deliver
to the correct user. This is what this option is
for.
--configdump
Parse the ~/.fetchmailrc file, interpret any com
mand-line options specified, and dump a
configuration report to standard output. The con
figuration report is a data structure assignment in
the language Python. This option is meant to be
used with an interactive ~/.fetchmailrc editor like
fetchmailconf, written in Python.
USER AUTHENTICATION AND ENCRYPTION
All modes except ETRN require authentication of the client
to the server. Normal user authentication in fetchmail is
very much like the authentication mechanism of ftp(1).
The correct user-id and password depend upon the underly
ing security system at the mailserver.
If the mailserver is a Unix machine on which you have an
ordinary user account, your regular login name and pass
word are used with fetchmail. If you use the same login
name on both the server and the client machines, you
needn't worry about specifying a user-id with the -u
option -- the default behavior is to use your login name
on the client machine as the user-id on the server
machine. If you use a different login name on the server
machine, specify that login name with the -u option. e.g.
if your login name is 'jsmith' on a machine named 'mail
grunt', you would start fetchmail as follows:
fetchmail-u jsmith mailgrunt
The default behavior of fetchmail is to prompt you for
your mailserver password before the connection is estab
lished. This is the safest way to use fetchmail and
ensures that your password will not be compromised. You
may also specify your password in your ~/.fetchmailrc
file. This is convenient when using fetchmail in daemon
mode or with scripts.
If you do not specify a password, and fetchmail cannot
extract one from your ~/.fetchmailrc file, it will look
for a ~/.netrc file in your home directory before request
ing one interactively; if an entry matching the mailserver
is found in that file, the password will be used. Fetch
mail first looks for a match on poll name; if it finds
none, it checks for a match on via name. See the ftp(1)
man page for details of the syntax of the ~/.netrc file.
(This feature may allow you to avoid duplicating password
information in more than one file.)
On mailservers that do not provide ordinary user accounts,
your user-id and password are usually assigned by the
server administrator when you apply for a mailbox on the
server. Contact your server administrator if you don't
know the correct user-id and password for your mailbox
account.
Early versions of POP3 (RFC1081, RFC1225) supported a
crude form of independent authentication using the rhosts
file on the mailserver side. Under this RPOP variant, a
fixed per-user ID equivalent to a password was sent in
clear over a link to a reserved port, with the command
RPOP rather than PASS to alert the server that it should
do special checking. RPOP is supported by fetchmail (you
can specify `protocol RPOP' to have the program send
`RPOP' rather than `PASS') but its use is strongly dis
couraged. This facility was vulnerable to spoofing and
was withdrawn in RFC1460.
RFC1460 introduced APOP authentication. In this variant
of POP3, you register an APOP password on your server host
(the program to do this with on the server is probably
called popauth(8)). You put the same password in your
~/.fetchmailrc file. Each time fetchmail logs in, it
sends a cryptographically secure hash of your password and
the server greeting time to the server, which can verify
it by checking its authorization database.
If your fetchmail was built with Kerberos support and you
specify Kerberos authentication (either with --auth or the
.fetchmailrc option authenticate kerberos_v4) it will try
to get a Kerberos ticket from the mailserver at the start
of each query. Note: if either the pollnane or via name
is `hesiod', fetchmail will try to use Hesiod to look up
the mailserver.
If you use POP3 or IMAP with GSSAPI authentication, fetch_
mail will expect the server to have RFC1731- or
RFC1734-conformant GSSAPI capability, and will use it.
Currently this has only been tested over Kerberos V, so
you're expected to already have a ticket-granting ticket.
You may pass a username different from your principal name
using the standard --user command or by the .fetchmailrc
option user.
If your IMAP daemon returns the PREAUTH response in its
greeting line, fetchmail will notice this and skip the
normal authentication step. This can be useful, e.g. if
you start imapd explicitly using ssh. In this case you
can declare the authentication value `ssh' on that site
entry to stop .fetchmail from asking you for a password
when it starts up.
If you are using POP3, and the server issues a one-time-
password challenge conforming to RFC1938, fetchmail will
use your password as a pass phrase to generate the
required response. This avoids sending secrets over the
net unencrypted.
Compuserve's RPA authentication (similar to APOP) is sup
ported. If you compile in the support, fetchmail will try
to perform an RPA pass-phrase authentication instead of
sending over the password en clair if it detects "@com
puserve.com" in the hostname.
If you are using IMAP, Microsoft's NTLM authentication
(used by Microsoft Exchange) is supported. If you compile
in the support, fetchmail will try to perform an NTLM
authentication (instead of sending over the password en
clair) whenever the server returns AUTH=NTLM in its capa
bility response. Specify a user option value that looks
like `user@domain': the part to the left of the @ will be
passed as the username and the part to the right as the
NTLM domain.
If you are using IPsec, the -T (--netsec) option can be
used to pass an IP security request to be used when outgo
ing IP connections are initialized. You can also do this
using the `netsec' server option in the .fetchmailrc file.
In either case, the option value is a string in the format
accepted by the net_security_strtorequest() function of
the inet6_apps library.
You can access SSL encrypted services by specifying the
--ssl option. You can also do this using the "ssl" server
option in the .fetchmailrc file. With SSL encryption
enabled, queries are initiated over a connection after
negotiating an SSL session. Some services, such as POP3
and IMAP, have different well known ports defined for the
SSL encrypted services. The encrypted ports will be
selected automatically when SSL is enabled and no explicit
port is specified.
When connecting to an SSL encrypted server, the server
presents a certificate to the client for validation. The
certificate is checked to verify that the common name in
the certificate matches the name of the server being con
tacted and that the effective and expiration dates in the
certificate indicate that it is currently valid. If any
of these checks fail, a warning message is printed, but
the connection continues. The server certificate does not
need to be signed by any specific Certifying Authority and
may be a "self-signed" certificate.
Some SSL encrypted servers may request a client side cer
tificate. A client side public SSL certificate and pri
vate SSL key may be specified. If requested by the
server, the client certificate is sent to the server for
validation. Some servers may require a valid client cer
tificate and may refuse connections if a certificate is
not provided or if the certificate is not valid. Some
servers may require client side certificates be signed by
a recognized Certifying Authority. The format for the key
files and the certificate files is that required by the
underlying SSL libraries (OpenSSL in the general case).
A word of care about the use of SSL: While above mentioned
setup with self-signed server certificates retrieved over
the wires can protect you from a passive eavesdropper it
doesn't help against an active attacker. It's clearly an
improvement over sending the passwords in clear but you
should be aware that a man-in-the-middle attack is triv
ially possible (in particular with tools such as dsniff,
http://www.monkey.org/~dugsong/dsniff/). Use of an ssh
tunnel (see below for some examples) is preferable if you
care seriously about the security of your mailbox.
fetchmail also supports authentication to the ESMTP server
on the client side according to RFC 2554. You can specify
a name/password pair to be used with the keywords `esmtp
name' and `esmtppassword'; the former defaults to the
username of the calling user.
DAEMON MODE
The --daemon <interval> or -d <interval> option runs
fetchmail in daemon mode. You must specify a numeric
argument which is a polling interval in seconds.
In daemon mode, fetchmail puts itself in background and
runs forever, querying each specified host and then sleep
ing for the given polling interval.
Simply invoking
fetchmail-d 900
will, therefore, poll all the hosts described in your
~/.fetchmailrc file (except those explicitly excluded with
the `skip' verb) once every fifteen minutes.
It is possible to set a polling interval in your ~/.fetch_
mailrc file by saying `set daemon <interval>', where
<interval> is an integer number of seconds. If you do
this, fetchmail will always start in daemon mode unless
you override it with the command-line option --daemon 0 or
-d0.
Only one daemon process is permitted per user; in daemon
mode, fetchmail makes a per-user lockfile to guarantee
this.
Normally, calling fetchmail with a daemon in the back
ground sends a wakeup signal to the daemon, forcing it to
poll mailservers immediately. (The wakeup signal is
SIGHUP if fetchmail is running as root, SIGUSR1 other
wise.) The wakeup action also clears any `wedged' flags
indicating that connections have wedged due to failed
authentication or multiple timeouts.
The option --quit will kill a running daemon process
instead of waking it up (if there is no such process,
fetchmail notifies you). If the --quit option is the only
command-line option, that's all there is to it.
The quit option may also be mixed with other command-line
options; its effect is to kill any running daemon before
doing what the other options specify in combination with
the rc file.
The -L <filename> or --logfile <filename> option (keyword:
set logfile) allows you to redirect status messages emit
ted while detached into a specified logfile (follow the
option with the logfile name). The logfile is opened for
append, so previous messages aren't deleted. This is pri
marily useful for debugging configurations.
The --syslog option (keyword: set syslog) allows you to
redirect status and error messages emitted to the sys_
log(3) system daemon if available. Messages are logged
with an id of fetchmail, the facility LOG_MAIL, and prior
ities LOG_ERR, LOG_ALERT or LOG_INFO. This option is
intended for logging status and error messages which indi
cate the status of the daemon and the results while fetch
ing mail from the server(s). Error messages for command
line options and parsing the .fetchmailrc file are still
written to stderr, or to the specified log file. The
--nosyslog option turns off use of syslog(3), assuming
it's turned on in the ~/.fetchmailrc file, or that the -L
or --logfile <file> option was used.
The -N or --nodetach option suppresses backgrounding and
detachment of the daemon process from its control termi
nal. This is primarily useful for debugging. Note that
this also causes the logfile option to be ignored (though
perhaps it shouldn't).
Note that while running in daemon mode polling a POP2 or
IMAP2bis server, transient errors (such as DNS failures or
sendmail delivery refusals) may force the fetchall option
on for the duration of the next polling cycle. This is a
robustness feature. It means that if a message is fetched
(and thus marked seen by the mailserver) but not delivered
locally due to some transient error, it will be re-fetched
during the next poll cycle. (The IMAP logic doesn't
delete messages until they're delivered, so this problem
does not arise.)
If you touch or change the ~/.fetchmailrc file while
fetchmail is running in daemon mode, this will be detected
at the beginning of the next poll cycle. When a changed
~/.fetchmailrc is detected, fetchmail rereads it and
restarts from scratch (using exec(2); no state information
is retained in the new instance). Note also that if you
break the ~/.fetchmailrc file's syntax, the new instance
will softly and silently vanish away on startup.
ADMINISTRATIVE OPTIONS
The --postmaster <name> option (keyword: set postmaster)
specifies the last-resort username to which multidrop mail
is to be forwarded if no matching local recipient can be
found. Normally this is just the user who invoked fetch_
mail. If the invoking user is root, then the default of
this option is the user `postmaster'. Setting postmaster
to the empty string causes such mail to be discarded.
The --nobounce option suppresses the normal action of
bouncing errors back to the sender in an RFC1894-confor
mant error message. If nobounce is on, the message will
go to the postmaster instead.
The --invisible option (keyword: set invisible) tries to
make fetchmail invisible. Normally, fetchmail behaves
like any other MTA would -- it generates a Received header
into each message describing its place in the chain of
transmission, and tells the MTA it forwards to that the
mail came from the machine fetchmail itself is running on.
If the invisible option is on, the Received header is sup
pressed and fetchmail tries to spoof the MTA it forwards
to into thinking it came directly from the mailserver
host.
The --showdots option (keyword: set showdots) forces
fetchmail to show progress dots even if the current tty is
not stdout (for example logfiles). Starting with fetch
mail version 5.3.0, progress dots are only shown on stdout
by default.
By specifying the --tracepolls option, you can ask fetch
mail to add information to the Received header on the form
"polling {label} account {user}", where {label} is the
account label (from the specified rcfile, normally
~/.fetchmailrc) and {user} is the username which is used
to log on to the mail server. This header can be used to
make filtering email where no useful header information is
available and you want mail from different accounts sorted
into different mailboxes (this could, for example, occur
if you have an account on the same server running a mail
ing list, and are subscribed to the list using that
account). The default is not adding any such header. In
.fetchmailrc, this is called `tracepolls'.
RETRIEVAL FAILURE MODES
The protocols fetchmail uses to talk to mailservers are
next to bulletproof. In normal operation forwarding to
port 25, no message is ever deleted (or even marked for
deletion) on the host until the SMTP listener on the
client side has acknowledged to fetchmail that the message
has been either accepted for delivery or rejected due to a
spam block.
When forwarding to an MDA, however, there is more possi
bility of error. Some MDAs are `safe' and reliably return
a nonzero status on any delivery error, even one due to
temporary resource limits. The well-known procmail(1)
program is like this; so are most programs designed as
mail transport agents, such as sendmail(1), and exim(1).
These programs give back a reliable positive acknowledge
ment and can be used with the mda option with no risk of
mail loss. Unsafe MDAs, though, may return 0 even on
delivery failure. If this happens, you will lose mail.
The normal mode of fetchmail is to try to download only
`new' messages, leaving untouched (and undeleted) messages
you have already read directly on the server (or fetched
with a previous fetchmail --keep). But you may find that
messages you've already read on the server are being
fetched (and deleted) even when you don't specify --all.
There are several reasons this can happen.
One could be that you're using POP2. The POP2 protocol
includes no representation of `new' or `old' state in mes
sages, so fetchmail must treat all messages as new all the
time. But POP2 is obsolete, so this is unlikely.
Under POP3, blame RFC1725. That version of the POP3 pro
tocol specification removed the LAST command, and some POP
servers follow it (you can verify this by invoking fetch_
mail -v to the mailserver and watching the response to
LAST early in the query). The fetchmail code tries to
compensate by using POP3's UID feature, storing the iden
tifiers of messages seen in each session until the next
session, in the .fetchids file. But this doesn't track
messages seen with other clients, or read directly with a
mailer on the host but not deleted afterward. A better
solution would be to switch to IMAP.
Another potential POP3 problem might be servers that
insert messages in the middle of mailboxes (some VMS
implementations of mail are rumored to do this). The
fetchmail code assumes that new messages are appended to
the end of the mailbox; when this is not true it may treat
some old messages as new and vice versa. The only real
fix for this problem is to switch to IMAP.
Yet another POP3 problem is that if they can't make temp
files in the user's home directory, some POP3 servers will
hand back an undocumented response that causes fetchmail
to spuriously report "No mail".
The IMAP code uses the presence or absence of the server
flag \Seen to decide whether or not a message is new.
Under Unix, it counts on your IMAP server to notice the
BSD-style Status flags set by mail user agents and set the
\Seen flag from them when appropriate. All Unix IMAP
servers we know of do this, though it's not specified by
the IMAP RFCs. If you ever trip over a server that
doesn't, the symptom will be that messages you have
already read on your host will look new to the server. In
this (unlikely) case, only messages you fetched with
fetchmail--keep will be both undeleted and marked old.
In ETRN and ODMR modes, fetchmail does not actually
retrieve messages; instead, it asks the server's SMTP lis
tener to start a queue flush to the client via SMTP.
Therefore it sends only undelivered messages.
SPAM FILTERING
Many SMTP listeners allow administrators to set up `spam
filters' that block unsolicited email from specified
domains. A MAIL FROM or DATA line that triggers this fea
ture will elicit an SMTP response which (unfortunately)
varies according to the listener.
Newer versions of sendmail return an error code of 571.
This return value is blessed by RFC1893 as "Delivery not
authorized, message refused".
According to RFC2821, the correct thing to return in this
situation is 550 "Requested action not taken: mailbox
unavailable" (the draft adds "[E.g., mailbox not found, no
access, or command rejected for policy reasons].").
Older versions of the exim MTA return 501 "Syntax error in
parameters or arguments".
The postfix MTA runs 554 as an antispam response.
Zmailer may reject code with a 500 response (followed by
an enhanced status code that contains more information).
Return codes which fetchmail treats as antispam responses
and discards the message can be set with the `antispam'
option. This is one of the only three circumstance under
which fetchmail ever discards mail (the others are the 552
and 553 errors described below, and the suppression of
multidropped messages with a message-ID already seen).
If fetchmail is fetching from an IMAP server, the antispam
response will be detected and the message rejected immedi
ately after the headers have been fetched, without reading
the message body. Thus, you won't pay for downloading
spam message bodies.
By default, the list of antispam responses is empty.
If the spambounce option is on, mail that is spam-blocked
triggers an RFC1892 bounce message informing the origina
tor that we do not accept mail from it.
SMTP/ESMTP ERROR HANDLING
Besides the spam-blocking described above, fetchmail takes
special actions on the following SMTP/ESMTP error
responses
452 (insufficient system storage)
Leave the message in the server mailbox for later
retrieval.
552 (message exceeds fixed maximum message size)
Delete the message from the server. Send bounce-mail
to the originator.
553 (invalid sending domain)
Delete the message from the server. Don't even try
to send bounce-mail to the originator.
Other errors trigger bounce mail back to the originator.
THE RUN CONTROL FILE
The preferred way to set up fetchmail is to write a
.fetchmailrc file in your home directory (you may do this
directly, with a text editor, or indirectly via fetchmail_
conf). When there is a conflict between the command-line
arguments and the arguments in this file, the command-line
arguments take precedence.
To protect the security of your passwords, when --version
is not on your ~/.fetchmailrc may not have more than 0600
(u=rw,g=,o=) permissions; fetchmail will complain and exit
otherwise.
You may read the .fetchmailrc file as a list of commands
to be executed when fetchmail is called with no arguments.
Run Control Syntax
Comments begin with a '#' and extend through the end of
the line. Otherwise the file consists of a series of
server entries or global option statements in a free-for
mat, token-oriented syntax.
There are four kinds of tokens: grammar keywords, numbers
(i.e. decimal digit sequences), unquoted strings, and
quoted strings. A quoted string is bounded by double
quotes and may contain whitespace (and quoted digits are
treated as a string). An unquoted string is any whites
pace-delimited token that is neither numeric, string
quoted nor contains the special characters `,', `;', `:',
or `='.
Any amount of whitespace separates tokens in server
entries, but is otherwise ignored. You may use standard C-
style escapes (\n, \t, \b, octal, and hex) to embed non-
printable characters or string delimiters in strings.
Each server entry consists of one of the keywords `poll'
or `skip', followed by a server name, followed by server
options, followed by any number of user descriptions.
Note: the most common cause of syntax errors is mixing up
user and server options.
For backward compatibility, the word `server' is a synonym
for `poll'.
You can use the noise keywords `and', `with', `has',
`wants', and `options' anywhere in an entry to make it
resemble English. They're ignored, but but can make
entries much easier to read at a glance. The punctuation
characters ':', ';' and ',' are also ignored.
Poll vs. Skip
The `poll' verb tells fetchmail to query this host when it
is run with no arguments. The `skip' verb tells fetchmail
not to poll this host unless it is explicitly named on the
command line. (The `skip' verb allows you to experiment
with test entries safely, or easily disable entries for
hosts that are temporarily down.)
Keyword/Option Summary
Here are the legal options. Keyword suffixes enclosed in
square brackets are optional. Those corresponding to com
mand-line options are followed by `-' and the appropriate
option letter.
Here are the legal global options:
Keyword Opt Function
-------------------------------------------------------------
set daemon Set a background poll interval in
seconds
set postmaster Give the name of the last-resort
mail recipient
set no bouncemail Direct error mail to postmaster
rather than sender
set no spambounce Send spam bounces
set logfile Name of a file to dump error and
status messages to
set idfile Name of the file to store UID
lists in
set syslog Do error logging through sys
log(3).
set nosyslog Turn off error logging through
syslog(3).
set properties String value is ignored by fetch
mail (may be used by extension
scripts)
Here are the legal server options:
Keyword Opt Function
------------------------------------------------------------
via Specify DNS name of mailserver,
overriding poll name
proto[col] -p Specify protocol (case insensi
tive): POP2, POP3, IMAP, APOP,
KPOP
local[domains] Specify domain(s) to be regarded
as local
port -P Specify TCP/IP service port
auth[enticate] Set authentication type (default
`any')
timeout -t Server inactivity timeout in sec
onds (default 300)
envelope -E Specify envelope-address header
name
no envelope Disable looking for envelope
address
qvirtual -Q Qmail virtual domain prefix to
remove from user name
aka Specify alternate DNS names of
mailserver
interface -I specify IP interface(s) that must
be up for server poll to take
place
monitor -M Specify IP address to monitor for
activity
plugin Specify command through which to
make server connections.
plugout Specify command through which to
make listener connections.
dns Enable DNS lookup for multidrop
(default)
no dns Disable DNS lookup for multidrop
checkalias Do comparison by IP address for
multidrop
no checkalias Do comparison by name for mul
tidrop (default)
uidl -U Force POP3 to use client-side
UIDLs
no uidl Turn off POP3 use of client-side
UIDLs (default)
interval Only check this site every N poll
cycles; N is a numeric argument.
netsec Pass in IPsec security option
request.
principal Set Kerberos principal (only use
ful with imap and kerberos)
esmtpname Set name for RFC2554 authentica
tion to the ESMTP server.
esmtppassword Set password for RFC2554 authenti
cation to the ESMTP server.
Here are the legal user options:
Keyword Opt Function
------------------------------------------------------------
user[name] -u Set remote user name (local user
name if name followed by `here')
is Connect local and remote user
names
to Connect local and remote user
names
pass[word] Specify remote account password
ssl Connect to server over the speci
fied base protocol using SSL
encryption
sslcert Specify file for client side pub
lic SSL certificate
sslkey Specify file for client side pri
vate SSL key
sslproto Force ssl protocol for connection
folder -r Specify remote folder to query
smtphost -S Specify smtp host(s) to forward to
fetchdomains Specify domains for which mail
should be fetched
smtpaddress -D Specify the domain to be put in
RCPT TO lines
smtpname Specify the user and domain to be
put in RCPT TO lines
antispam -Z Specify what SMTP returns are
interpreted as spam-policy blocks
mda -m Specify MDA for local delivery
bsmtp -o Specify BSMTP batch file to append
to
preconnect Command to be executed before each
connection
postconnect Command to be executed after each
connection
keep -k Don't delete seen messages from
server
flush -F Flush all seen messages before
querying
fetchall -a Fetch all messages whether seen or
not
rewrite Rewrite destination addresses for
reply (default)
stripcr Strip carriage returns from ends
of lines
forcecr Force carriage returns at ends of
lines
pass8bits Force BODY=8BITMIME to ESMTP lis
tener
dropstatus Strip Status and X-Mozilla-Status
lines out of incoming mail
dropdelivered Strip Delivered-To lines out of
incoming mail
mimedecode Convert quoted-printable to 8-bit
in MIME messages
idle Idle waiting for new messages
after each poll (IMAP only)
no keep -K Delete seen messages from server
(default)
no flush Don't flush all seen messages
before querying (default)
no fetchall Retrieve only new messages
(default)
no rewrite Don't rewrite headers
no stripcr Don't strip carriage returns
(default)
no forcecr Don't force carriage returns at
EOL (default)
no pass8bits Don't force BODY=8BITMIME to ESMTP
listener (default)
no dropstatus Don't drop Status headers
(default)
no dropdelivered Don't drop Delivered-To headers
(default)
no mimedecode Don't convert quoted-printable to
8-bit in MIME messages (default)
no idle Don't idle waiting for new mes
sages after each poll (IMAP only)
limit -l Set message size limit
warnings -w Set message size warning interval
batchlimit -b Max # messages to forward in sin
gle connect
fetchlimit -B Max # messages to fetch in single
connect
expunge -e Perform an expunge on every #th
message (IMAP and POP3 only)
tracepolls Add poll tracing information to
the Received header
properties String value is ignored by fetch
mail (may be used by extension
scripts)
Remember that all user options must follow all server
options.
In the .fetchmailrc file, the `envelope' string argument
may be preceded by a whitespace-separated number. This
number, if specified, is the number of such headers to
skip (that is, an argument of 1 selects the second header
of the given type). This is sometime useful for ignoring
bogus Received headers created by an ISP's local delivery
agent.
Keywords Not Corresponding To Option Switches
The `folder' and `smtphost' options (unlike their command-
line equivalents) can take a space- or comma-separated
list of names following them.
All options correspond to the obvious command-line argu
ments, except the following: `via', `interval', `aka',
`is', `to', `dns'/`no dns', `checkalias'/`no checkalias',
`password', `preconnect', `postconnect', `localdomains',
`stripcr'/`no stripcr', `forcecr'/`no forcecr',
`pass8bits'/`no pass8bits' `dropstatus/no dropstatus',
`dropdelivered/no dropdelivered', `mimedecode/no mimede
code', `idle/no idle', and `no envelope'.
The `via' option is for if you want to have more than one
configuration pointing at the same site. If it is pre
sent, the string argument will be taken as the actual DNS
name of the mailserver host to query. This will override
the argument of poll, which can then simply be a distinct
label for the configuration (e.g. what you would give on
the command line to explicitly query this host).
The `interval' option (which takes a numeric argument)
allows you to poll a server less frequently than the basic
poll interval. If you say `interval N' the server this
option is attached to will only be queried every N poll
intervals.
The `is' or `to' keywords associate the following local
(client) name(s) (or server-name to client-name mappings
separated by =) with the mailserver user name in the
entry. If an is/to list has `*' as its last name, unrec
ognized names are simply passed through.
A single local name can be used to support redirecting
your mail when your username on the client machine is dif
ferent from your name on the mailserver. When there is
only a single local name, mail is forwarded to that local
username regardless of the message's Received, To, Cc, and
Bcc headers. In this case fetchmail never does DNS
lookups.
When there is more than one local name (or name mapping)
the fetchmail code does look at the Received, To, Cc, and
Bcc headers of retrieved mail (this is `multidrop mode').
It looks for addresses with hostname parts that match your
poll name or your `via', `aka' or `localdomains' options,
and usually also for hostname parts which DNS tells it are
aliases of the mailserver. See the discussion of `dns',
`checkalias', `localdomains', and `aka' for details on how
matching addresses are handled.
If fetchmail cannot match any mailserver usernames or
localdomain addresses, the mail will be bounced. Normally
it will be bounced to the sender, but if `nobounce' is on
it will go to the postmaster (which in turn defaults to
being the calling user).
The `dns' option (normally on) controls the way addresses
from multidrop mailboxes are checked. On, it enables
logic to check each host address that doesn't match an
`aka' or `localdomains' declaration by looking it up with
DNS. When a mailserver username is recognized attached to
a matching hostname part, its local mapping is added to
the list of local recipients.
The `checkalias' option (normally off) extends the lookups
performed by the `dns' keyword in multidrop mode, provid
ing a way to cope with remote MTAs that identify them
selves using their canonical name, while they're polled
using an alias. When such a server is polled, checks to
extract the envelope address fail, and fetchmail reverts
to delivery using the To/Cc/Bcc headers (See below `Header
vs. Envelope addresses'). Specifying this option
instructs fetchmail to retrieve all the IP addresses asso
ciated with both the poll name and the name used by the
remote MTA and to do a comparison of the IP addresses.
This comes in handy in situations where the remote server
undergoes frequent canonical name changes, that would oth
erwise require modifications to the rcfile. `checkalias'
has no effect if `no dns' is specified in the rcfile.
The `aka' option is for use with multidrop mailboxes. It
allows you to pre-declare a list of DNS aliases for a
server. This is an optimization hack that allows you to
trade space for speed. When fetchmail, while processing a
multidrop mailbox, grovels through message headers looking
for names of the mailserver, pre-declaring common ones can
save it from having to do DNS lookups. Note: the names
you give as arguments to `aka' are matched as suffixes --
if you specify (say) `aka netaxs.com', this will match not
just a hostnamed netaxs.com, but any hostname that ends
with `.netaxs.com'; such as (say) pop3.netaxs.com and
mail.netaxs.com.
The `localdomains' option allows you to declare a list of
domains which fetchmail should consider local. When
fetchmail is parsing address lines in multidrop modes, and
a trailing segment of a host name matches a declared local
domain, that address is passed through to the listener or
MDA unaltered (local-name mappings are not applied).
If you are using `localdomains', you may also need to
specify `no envelope', which disables fetchmail's normal
attempt to deduce an envelope address from the Received
line or X-Envelope-To header or whatever header has been
previously set by `envelope'. If you set `no envelope' in
the defaults entry it is possible to undo that in individ
ual entries by using `envelope <string>'. As a special
case, `envelope "Received"' restores the default parsing
of Received lines.
The password option requires a string argument, which is
the password to be used with the entry's server.
The `preconnect' keyword allows you to specify a shell
command to be executed just before each time fetchmail
establishes a mailserver connection. This may be useful
if you are attempting to set up secure POP connections
with the aid of ssh(1). If the command returns a nonzero
status, the poll of that mailserver will be aborted.
Similarly, the `postconnect' keyword similarly allows you
to specify a shell command to be executed just after each
time a mailserver connection is taken down.
The `forcecr' option controls whether lines terminated by
LF only are given CRLF termination before forwarding.
Strictly speaking RFC821 requires this, but few MTAs
enforce the requirement it so this option is normally off
(only one such MTA, qmail, is in significant use at time
of writing).
The `stripcr' option controls whether carriage returns are
stripped out of retrieved mail before it is forwarded. It
is normally not necessary to set this, because it defaults
to `on' (CR stripping enabled) when there is an MDA
declared but `off' (CR stripping disabled) when forwarding
is via SMTP. If `stripcr' and `forcecr' are both on,
`stripcr' will override.
The `pass8bits' option exists to cope with Microsoft mail
programs that stupidly slap a "Content-Transfer-Encoding:
7bit" on everything. With this option off (the default)
and such a header present, fetchmail declares BODY=7BIT to
an ESMTP-capable listener; this causes problems for
messages actually using 8-bit ISO or KOI-8 character sets,
which will be garbled by having the high bits of all char
acters stripped. If `pass8bits' is on, fetchmail is
forced to declare BODY=8BITMIME to any ESMTP-capable lis
tener. If the listener is 8-bit-clean (as all the major
ones now are) the right thing will probably result.
The `dropstatus' option controls whether nonempty Status
and X-Mozilla-Status lines are retained in fetched mail
(the default) or discarded. Retaining them allows your
MUA to see what messages (if any) were marked seen on the
server. On the other hand, it can confuse some new-mail
notifiers, which assume that anything with a Status line
in it has been seen. (Note: the empty Status lines
inserted by some buggy POP servers are unconditionally
discarded.)
The `dropdelivered' option controls wether Delivered-To
headers will be kept in fetched mail (the default) or dis
carded. These headers are added by Qmail and Postfix
mailservers in order to avoid mail loops but may get in
your way if you try to "mirror" a mailserver within the
same domain. Use with caution.
The `mimedecode' option controls whether MIME messages
using the quoted-printable encoding are automatically con
verted into pure 8-bit data. If you are delivering mail to
an ESMTP-capable, 8-bit-clean listener (that includes all
of the major MTAs like sendmail), then this will automati
cally convert quoted-printable message headers and data
into 8-bit data, making it easier to understand when read
ing mail. If your e-mail programs know how to deal with
MIME messages, then this option is not needed. The
mimedecode option is off by default, because doing RFC2047
conversion on headers throws away character-set informa
tion and can lead to bad results if the encoding of the
headers differs from the body encoding.
The `idle' option is usable only with IMAP servers sup
porting the RFC2177 IDLE command extension. If it is
enabled, and fetchmail detects that IDLE is supported, an
IDLE will be issued at the end of each poll. This will
tell the IMAP server to hold the connection open and
notify the client when new mail is available. If you need
to poll a link frequently, IDLE can save bandwidth by
eliminating TCP/IP connects and LOGIN/LOGOUT sequences. On
the other hand, an IDLE connection will eat almost all of
your fetchmail's time, because it will never drop the con
nection and allow other pools to occur unless the server
times out the IDLE. It also doesn't work with multiple
folders; only the first folder will ever be polled.
The `properties' option is an extension mechanism. It
takes a string argument, which is ignored by fetchmail
itself. The string argument may be used to store configu
ration information for scripts which require it. In par
ticular, the output of `--configdump' option will make
properties associated with a user entry readily available
to a Python script.
Miscellaneous Run Control Options
The words `here' and `there' have useful English-like sig
nificance. Normally `user eric is esr' would mean that
mail for the remote user `eric' is to be delivered to
`esr', but you can make this clearer by saying `user eric
there is esr here', or reverse it by saying `user esr here
is eric there'
Legal protocol identifiers for use with the `protocol'
keyword are:
auto (or AUTO)
pop2 (or POP2)
pop3 (or POP3)
sdps (or SDPS)
imap (or IMAP)
apop (or APOP)
kpop (or KPOP)
Legal authentication types are `any', `password', `ker
beros', 'kereberos_v5' and `gssapi', `cram-md5', `otp',
`ntlm', `ssh`. The `password' type specifies authentica
tion by normal transmission of a password (the password
may be plaintext or subject to protocol-specific encryp
tion as in APOP); `kerberos' tells fetchmail to try to get
a Kerberos ticket at the start of each query instead, and
send an arbitrary string as the password; and `gssapi'
tells fetchmail to use GSSAPI authentication. See the
description of the `auth' keyword for more.
Specifying `kpop' sets POP3 protocol over port 1109 with
Kerberos V4 authentication. These defaults may be over
ridden by later options.
There are currently four global option statements; `set
logfile' followed by a string sets the same global speci
fied by --logfile. A command-line --logfile option will
override this. Also, `set daemon' sets the poll interval
as --daemon does. This can be overridden by a command-
line --daemon option; in particular --daemon 0 can be used
to force foreground operation. The `set postmaster' state
ment sets the address to which multidrop mail defaults if
there are no local matches. Finally, `set syslog' sends
log messages to syslogd(8).
INTERACTION WITH RFC 822
When trying to determine the originating address of a mes
sage, fetchmail looks through headers in the following
order:
Return-Path:
Resent-Sender: (ignored if it doesn't contain an @ or !)
Sender: (ignored if it doesn't contain an @ or !)
Resent-From:
From:
Reply-To:
Apparently-From:
The originating address is used for logging, and to set
the MAIL FROM address when forwarding to SMTP. This order
is intended to cope gracefully with receiving mailing list
messages in multidrop mode. The intent is that if a local
address doesn't exist, the bounce message won't be
returned blindly to the author or to the list itself, but
rather to the list manager (which is less annoying).
In multidrop mode, destination headers are processed as
follows: First, fetchmail looks for the Received: header
(or whichever one is specified by the `envelope' option)
to determine the local recipient address. If the mail is
addressed to more than one recipient, the Received line
won't contain any information regarding recipient
addresses.
Then fetchmail looks for the Resent-To:, Resent-Cc:, and
Resent-Bcc: lines. If they exists, they should contain
the final recipients and have precedence over their
To:/Cc:/Bcc: counterparts. If the Resent-* lines doesn't
exist, the To:, Cc:, Bcc: and Apparently-To: lines are
looked for. (The presence of a Resent-To: is taken to
imply that the person referred by the To: address has
already received the original copy of the mail).
CONFIGURATION EXAMPLES
Note that although there are password declarations in a
good many of the examples below, this is mainly for illus
trative purposes. We recommend stashing account/password
pairs in your $HOME/.netrc file, where they can be used
not just by fetchmail but by ftp(1) and other programs.
Basic format is:
poll SERVERNAME protocol PROTOCOL username NAME password PASSWORD
Example:
poll pop.provider.net protocol pop3 username "jsmith" password "secret1"
Or, using some abbreviations:
poll pop.provider.net proto pop3 user "jsmith" password "secret1"
Multiple servers may be listed:
poll pop.provider.net proto pop3 user "jsmith" pass "secret1"
poll other.provider.net proto pop2 user "John.Smith" pass "My^Hat"
Here's a version of those two with more whitespace and
some noise words:
poll pop.provider.net proto pop3
user "jsmith", with password secret1, is "jsmith" here;
poll other.provider.net proto pop2:
user "John.Smith", with password "My^Hat", is "John.Smith" here;
This version is much easier to read and doesn't cost sig
nificantly more (parsing is done only once, at startup
time).
If you need to include whitespace in a parameter string,
enclose the string in double quotes. Thus:
poll mail.provider.net with proto pop3:
user "jsmith" there has password "u can't krak this"
is jws here and wants mda "/bin/mail"
You may have an initial server description headed by the
keyword `defaults' instead of `poll' followed by a name.
Such a record is interpreted as defaults for all queries
to use. It may be overwritten by individual server
descriptions. So, you could write:
defaults proto pop3
user "jsmith"
poll pop.provider.net
pass "secret1"
poll mail.provider.net
user "jjsmith" there has password "secret2"
It's possible to specify more than one user per server
(this is only likely to be useful when running fetchmail
in daemon mode as root). The `user' keyword leads off a
user description, and every user specification in a multi-
user entry must include it. Here's an example:
poll pop.provider.net proto pop3 port 3111
user "jsmith" with pass "secret1" is "smith" here
user jones with pass "secret2" is "jjones" here keep
This associates the local username `smith' with the
pop.provider.net username `jsmith' and the local username
`jjones' with the pop.provider.net username `jones'. Mail
for `jones' is kept on the server after download.
Here's what a simple retrieval configuration for a multi-
drop mailbox looks like:
poll pop.provider.net:
user maildrop with pass secret1 to golux 'hurkle'='happy' snark here
This says that the mailbox of account `maildrop' on the
server is a multi-drop box, and that messages in it should
be parsed for the server user names `golux', `hurkle', and
`snark'. It further specifies that `golux' and `snark'
have the same name on the client as on the server, but
mail for server user `hurkle' should be delivered to
client user `happy'.
Here's an example of another kind of multidrop connection:
poll pop.provider.net localdomains loonytoons.org toons.org:
user maildrop with pass secret1 to * here
This also says that the mailbox of account `maildrop' on
the server is a multi-drop box. It tells fetchmail that
any address in the loonytoons.org or toons.org domains
(including subdomain addresses like `joe@daffy.loony
toons.org') should be passed through to the local SMTP
listener without modification. Be careful of mail loops
if you do this!
Here's an example configuration using ssh and the plugin
option. The queries are made directly on the stdin and
stdout of imapd via ssh. Note that in this setup, IMAP
authentication can be skipped.
poll mailhost.net with proto imap:
plugin "ssh %h /usr/sbin/imapd" auth ssh;
user esr is esr here
THE USE AND ABUSE OF MULTIDROP MAILBOXES
Use the multiple-local-recipients feature with caution --
it can bite. All multidrop features are ineffective in
ETRN and ODMR modes.
Also, note that in multidrop mode duplicate mails are sup
pressed. A piece of mail is considered duplicate if it
has the same message-ID as the message immediately
preceding and more than one addressee. Such runs of mes
sages may be generated when copies of a message addressed
to multiple users are delivered to a multidrop box.
Header vs. Envelope addresses
The fundamental problem is that by having your mailserver
toss several peoples' mail in a single maildrop box, you
may have thrown away potentially vital information about
who each piece of mail was actually addressed to (the
`envelope address', as opposed to the header addresses in
the RFC822 To/Cc/Bcc headers). This `envelope address' is
the address you need in order to reroute mail properly.
Sometimes fetchmail can deduce the envelope address. If
the mailserver MTA is sendmail and the item of mail had
just one recipient, the MTA will have written a `by/for'
clause that gives the envelope addressee into its Received
header. But this doesn't work reliably for other MTAs, nor
if there is more than one recipient. By default, fetch_
mail looks for envelope addresses in these lines; you can
restore this default with -E "Received" or `envelope
Received'.
Alternatively, some SMTP listeners and/or mail servers
insert a header in each message containing a copy of the
envelope addresses. This header (when it exists) is often
`X-Envelope-To'. Fetchmail's assumption about this can be
changed with the -E or `envelope' option. Note that writ
ing an envelope header of this kind exposes the names of
recipients (including blind-copy recipients) to all
receivers of the messages; it is therefore regarded by
some administrators as a security/privacy problem.
A slight variation of the `X-Envelope-To' header is the
`Delivered-To' put by qmail to avoid mail loops. It will
probably prefix the user name with a string that normally
matches the user's domain. To remove this prefix you can
use the -Q or `qvirtual' option.
Sometimes, unfortunately, neither of these methods works.
When they all fail, fetchmail must fall back on the con
tents of To/Cc/Bcc headers to try to determine recipient
addressees -- and these are not reliable. In particular,
mailing-list software often ships mail with only the list
broadcast address in the To header.
When fetchmail cannot deduce a recipient address that is
local, and the intended recipient address was anyone other
than fetchmail's invoking user, mail will get lost. This
is what makes the multidrop feature risky.
A related problem is that when you blind-copy a mail mes
sage, the Bcc information is carried only as envelope
address (it's not put in the headers fetchmail can see
unless there is an X-Envelope header). Thus, blind-copy
ing to someone who gets mail over a fetchmail link will
fail unless the the mailserver host routinely writes X-
Envelope or an equivalent header into messages in your
maildrop.
Good Ways To Use Multidrop Mailboxes
Multiple local names can be used to administer a mailing
list from the client side of a fetchmail collection. Sup
pose your name is `esr', and you want to both pick up your
own mail and maintain a mailing list called (say) "fetch
mail-friends", and you want to keep the alias list on your
client machine.
On your server, you can alias `fetchmail-friends' to
`esr'; then, in your .fetchmailrc, declare `to esr fetch
mail-friends here'. Then, when mail including `fetchmail-
friends' as a local address gets fetched, the list name
will be appended to the list of recipients your SMTP lis
tener sees. Therefore it will undergo alias expansion
locally. Be sure to include `esr' in the local alias
expansion of fetchmail-friends, or you'll never see mail
sent only to the list. Also be sure that your listener
has the "me-too" option set (sendmail's -oXm command-line
option or OXm declaration) so your name isn't removed from
alias expansions in messages you send.
This trick is not without its problems, however. You'll
begin to see this when a message comes in that is
addressed only to a mailing list you do not have declared
as a local name. Each such message will feature an `X-
Fetchmail-Warning' header which is generated because
fetchmail cannot find a valid local name in the recipient
addresses. Such messages default (as was described above)
to being sent to the local user running fetchmail, but the
program has no way to know that that's actually the right
thing.
Bad Ways To Abuse Multidrop Mailboxes
Multidrop mailboxes and fetchmail serving multiple users
in daemon mode do not mix. The problem, again, is mail
from mailing lists, which typically does not have an indi
vidual recipient address on it. Unless fetchmail can
deduce an envelope address, such mail will only go to the
account running fetchmail (probably root). Also, blind-
copied users are very likely never to see their mail at
all.
If you're tempted to use fetchmail to retrieve mail for
multiple users from a single mail drop via POP or IMAP,
think again (and reread the section on header and envelope
addresses above). It would be smarter to just let the
mail sit in the mailserver's queue and use fetchmail's
ETRN or ODMR modes to trigger SMTP sends periodically (of
course, this means you have to poll more frequently than
the mailserver's expiry period). If you can't arrange
this, try setting up a UUCP feed.
If you absolutely must use multidrop for this purpose,
make sure your mailserver writes an envelope-address
header that fetchmail can see. Otherwise you will lose
mail and it will come back to haunt you.
Speeding Up Multidrop Checking
Normally, when multiple users are declared fetchmail
extracts recipient addresses as described above and checks
each host part with DNS to see if it's an alias of the
mailserver. If so, the name mappings described in the to
... here declaration are done and the mail locally deliv
ered.
This is the safest but also slowest method. To speed it
up, pre-declare mailserver aliases with `aka'; these are
checked before DNS lookups are done. If you're certain
your aka list contains all DNS aliases of the mailserver
(and all MX names pointing at it) you can declare `no dns'
to suppress DNS lookups entirely and only match against
the aka list.
EXIT CODES
To facilitate the use of fetchmail in shell scripts, an
exit code is returned to give an indication of what
occurred during a given connection.
The exit codes returned by fetchmail are as follows:
0 One or more messages were successfully retrieved
(or, if the -c option was selected, were found
waiting but not retrieved).
1 There was no mail awaiting retrieval. (There may
have been old mail still on the server but not
selected for retrieval.)
2 An error was encountered when attempting to open a
socket to retrieve mail. If you don't know what a
socket is, don't worry about it -- just treat this
as an 'unrecoverable error'. This error can also
be because a protocol fetchmail wants to use is not
listed in /etc/services.
3 The user authentication step failed. This usually
means that a bad user-id, password, or APOP id was
specified. Or it may mean that you tried to run
fetchmail under circumstances where it did not have
standard input attached to a terminal and could not
prompt for a missing password.
4 Some sort of fatal protocol error was detected.
5 There was a syntax error in the arguments to fetch_
mail.
6 The run control file had bad permissions.
7 There was an error condition reported by the
server. Can also fire if fetchmail timed out while
waiting for the server.
8 Client-side exclusion error. This means fetchmail
either found another copy of itself already run
ning, or failed in such a way that it isn't sure
whether another copy is running.
9 The user authentication step failed because the
server responded "lock busy". Try again after a
brief pause! This error is not implemented for all
protocols, nor for all servers. If not implemented
for your server, "3" will be returned instead, see
above. May be returned when talking to qpopper or
other servers that can respond with "lock busy" or
some similar text containing the word "lock".
10 The fetchmail run failed while trying to do an SMTP
port open or transaction.
11 Fatal DNS error. Fetchmail encountered an error
while performing a DNS lookup at startup and could
not proceed.
12 BSMTP batch file could not be opened.
13 Poll terminated by a fetch limit (see the --fetch
limit option).
14 Server busy indication.
23 Internal error. You should see a message on stan
dard error with details.
When fetchmail queries more than one host, return status
is 0 if any query successfully retrieved mail. Otherwise
the returned error status is that of the last host
queried.
FILES
~/.fetchmailrc
default run control file
~/.fetchids
default location of file associating hosts with last
message IDs seen (used only with newer RFC1725-com
pliant POP3 servers supporting the UIDL command).
~/.fetchmail.pid
lock file to help prevent concurrent runs (non-root
mode).
~/.netrc
your FTP run control file, which (if present) will be
searched for passwords as a last resort before
prompting for one interactively.
/var/run/fetchmail.pid
lock file to help prevent concurrent runs (root mode,
Linux systems).
/etc/fetchmail.pid
lock file to help prevent concurrent runs (root mode,
systems without /var/run).
ENVIRONMENT
If the FETCHMAILUSER variable is set, it is used as the
name of the calling user (default local name) for purposes
such as mailing error notifications. Otherwise, if either
the LOGNAME or USER variable is correctly set (e.g. the
corresponding UID matches the session user ID) then that
name is used as the default local name. Otherwise getp
wuid(3) must be able to retrieve a password entry for the
session ID (this elaborate logic is designed to handle the
case of multiple names per userid gracefully).
If the environment variable FETCHMAILHOME is set to a
valid and existing directory name, the .fetchmailrc and
.fetchids and .fetchmail.pid files are put there instead
of in the invoking user's home directory (and lose the
leading dots on their names). The .netrc file is looked
for in the the invoking user's home directory regardless
of FETCHMAILHOME's setting.
SIGNALS
If a fetchmail daemon is running as root, SIGHUP wakes it
up from its sleep phase and forces a poll of all non-
skipped servers (this is in accordance with the usual con
ventions for system daemons).
If fetchmail is running in daemon mode as non-root, use
SIGUSR1 to wake it (this is so SIGHUP due to logout can
retain the default action of killing it).
Running fetchmail in foreground while a background fetch
mail is running will do whichever of these is appropriate
to wake it up.
BUGS AND KNOWN PROBLEMS
The mda and plugin options interact badly. In order to
collect error status from the MDA, fetchmail has to change
its normal signal handling so that dead plugin processes
don't get reaped until the end of the poll cycle. This
can cause resource starvation if too many zombies accumu
late. So either don't deliver to a MDA using plugins or
risk being overrun by an army of undead.
The RFC822 address parser used in multidrop mode chokes on
some @-addresses that are technically legal but bizarre.
Strange uses of quoting and embedded comments are likely
to confuse it.
In a message with multiple envelope headers, only the last
one processed will be visible to fetchmail. To get around
this, use a mailserver-side filter that consolidates the
contents of all envelope headers into a single one (proc
mail, mailagent, or maildrop can be programmed to do this
fairly easily).
Use of some of these protocols requires that the program
send unencrypted passwords over the TCP/IP connection to
the mailserver. This creates a risk that name/password
pairs might be snaffled with a packet sniffer or more
sophisticated monitoring software. Under Linux and
FreeBSD, the --interface option can be used to restrict
polling to availability of a specific interface device
with a specific local or remote IP address, but snooping
is still possible if (a) either host has a network device
that can be opened in promiscuous mode, or (b) the inter
vening network link can be tapped. We recommend the use
of ssh(1) tunnelling to not only shroud your passwords but
encrypt the entire conversation.
Use of the %F or %T escapes in an mda option could open a
security hole, because they pass text manipulable by an
attacker to a shell command. Potential shell characters
are replaced by `_' before execution. The hole is further
reduced by the fact that fetchmail temporarily discards
any suid privileges it may have while running the MDA.
For maximum safety, however, don't use an mda command con
taining %F or %T when fetchmail is run from the root
account itself.
Fetchmail's method of sending bouncemail and spam bounces
requires that port 25 of localhost be available for send
ing mail via SMTP.
If you modify a ~/.fetchmailrc while a background instance
is running and break the syntax, the background instance
will die silently. Unfortunately, it can't die noisily
because we don't yet know whether syslog should be
enabled. On some systems, fetchmail dies quietly even if
there is no syntax error; this seems to have something to
do with buggy terminal ioctl code in the kernel.
The -f - option (reading a configuration from stdin) is
incompatible with the plugin option.
The UIDL code is generally flaky and tends to lose its
state on errors and line drops (so that old messages are
re-seen). If this happens to you, switch to IMAP4.
The `principal' option only handles Kerberos IV, not V.
Send comments, bug reports, gripes, and the like to the
fetchmail-friends list <fetchmail-friends@lists.ccil.org>.
An HTML FAQ is available at the fetchmail home page; surf
to http://www.tuxedo.org/~esr/fetchmail or do a WWW search
for pages with `fetchmail' in their titles.
AUTHOR
Eric S. Raymond <esr@snark.thyrsus.com>. Too many other
people to name here have contributed code and patches.
This program is descended from and replaces popclient, by
Carl Harris <ceharris@mal.com>; the internals have become
quite different, but some of its interface design is
directly traceable to that ancestral program.
SEE ALSOmutt(1), elm(1), mail(1), sendmail(8), popd(8), imapd(8),
netrc(5)APPLICABLE STANDARDS
SMTP/ESMTP:
RFC 821, RFC2821, RFC 1869, RFC 1652, RFC 1870, RFC
1983, RFC 1985, RFC 2554.
mail:
RFC 822, RFC2822, RFC 1123, RFC 1892, RFC 1894.
POP2:
RFC 937
POP3:
RFC 1081, RFC 1225, RFC 1460, RFC 1725, RFC1734, RFC
1939, RFC 1957, RFC2195, RFC 2449.
APOP:
RFC 1460, RFC 1725, RFC 1939.
RPOP:
RFC 1081, RFC 1225.
IMAP2/IMAP2BIS:
RFC 1176, RFC 1732.
IMAP4/IMAP4rev1:
RFC 1730, RFC 1731, RFC 1732, RFC 2060, RFC 2061, RFC
2195, RFC 2177, RFC 2683.
ETRN:
RFC 1985.
ODMR/ATRN:
RFC 2645.
OTP: RFC 1938.
LMTP:
RFC 2033.
GSSAPI:
RFC 1508.
fetchmail(1)
