Penguin

exim

exim

NAME SYNOPSIS DESCRIPTION LIMITATIONS FEATURES METHOD OF OPERATION TRUSTED AND ADMIN USERS OPTIONS SEE ALSO AUTHOR


NAME

exim - Mail Transfer Agent

SYNOPSIS

exim [options? arguments ... mailq [options? arguments ... rmail [options? arguments ... rsmtp [options? arguments ... runq [options? arguments ... sendmail [options? arguments ...

DESCRIPTION

Exim is a mail transport agent (MTA) developed at the University of Cambridge for use on Unix systems connected to the Internet. It is freely available under the terms of the GNU General Public Licence. In style it is similar to Smail 3, but its facilities are more extensive, and in particular it has some defences against mail bombs and unsolicited junk mail, in the form of options for refusing messages from particular hosts, networks, or senders.

Exim's command line takes the standard Unix form of a sequence of options, each starting with a hyphen character, followed by a number of arguments. The options are compatible with the main options of Sendmail, and there are also some additional options, some of which are compatible with Smail 3. Certain combinations of options do not make sense, and provoke an error if used. The form of the arguments depends on which options are set.

If Exim is called under the name mailq, it behaves as if the option -bp were present before any other options. This is for compatibility with some systems that contain a command of that name in one of the standard libraries, symbolically linked to /usr/lib/sendmail.

If Exim is called under the name rsmtp it behaves as if the option -bS were present before any other options, for compatibility with smail. The -bS option is used for reading in a number of messages in batched SMTP format.

If Exim is called under the name rmail it behaves as if the option -i were present before any other options, for compatibility with smail. The -i option is used for reading a message that should not be terminated by a dot on a line by itself. The name rmail is used as an interface by some UUCP systems.

If Exim is called under the name runq it behaves as if the option -q were present before any other options, for compatibility with smail. The -q option causes a single queue-runner process to be started.

LIMITATIONS

For the benefit of those reading this overview to see whether Exim is of interest to them, its limitations are listed first.

ANSI-C

Exim is written in ANSI C. This should not be much of a limitation these days. However, to help with systems that lack a true ANSI C library, Exim avoids making any use of the value returned by the sprintf() function, which is one of the main incompatibilities. It has its own version of strerror() for use with SunOS4 and any other system that lacks this function, and a macro can be defined to turn memmove() into bcopy() if necessary.

Filenames

Exim uses file names that are longer than 14 characters.

Bangpaths

Exim is intended for use as an Internet mailer, and therefore handles addresses in RFC 822 domain format only. It cannot handle 'bang paths', though simple two-component bang paths can be converted by a straightforward rewriting configuration.

Domains required

Exim insists that every address it handles has a domain attached. For incoming local messages, domainless addresses are automatically qualified with a configured domain value. Configuration options specify from which remote systems unqualified addresses are acceptable.

Transports

The only external transport currently implemented is an SMTP transport over a TCP/IP network (using sockets), suitable for machines on the Internet. However, a pipe transport is available, and there are facilities for writing messages to files in 'batched SMTP' format; this can be used to send messages to some other transport mechanism. Batched SMTP input is also catered for.

FEATURES

Exim follows the same general approach of decentralized control that Smail 3 does. There is no central process doing overall management of mail delivery. However, unlike Smail, the independent delivery processes share data in the form of 'hints', which makes delivery more efficient in some cases. The hints are kept in a number of DBM files. If any of these files are lost, the only effect is to change the pattern of delivery attempts and retries.

Many configuration options can be given as expansion strings, and as these can include file lookups, much of Exim's operation can be made table-driven if desired. For example, it is possible to do local delivery on a machine on which the users do not have accounts.

Regular expressions are available in a number of configuration parameters.

Domain lists can include file lookups, making it possible to support a large number of local domains.

Exim has flexible retry algorithms, applicable to mail routing as well as to delivery.

Exim contains header and envelope rewriting facilities.

Unqualified addresses are accepted only from specified hosts or networks.

Exim can perform multiple deliveries down the same SMTP channel after deliveries to a host have been delayed.

Exim can be configured to do local deliveries immediately but to leave remote deliveries until the message is picked up by a queue-runner process. This increases the likelihood of multiple messages being sent down a single SMTP connection.

When copies of a message have to be delivered to more than one remote host, up to a configured maximum number of remote deliveries can be done in parallel.

Exim supports optional checking of incoming return path (sender) and receiver addresses as they are received by SMTP.

SMTP calls from specific machines, optionally from specific idents, can be locked out, and incoming SMTP messages from specific senders can also be locked out.

It is possible to control which hosts may use the Exim host as a relay for onward transmission of mail; the control can be made to depend on the address domain.

Messages on the queue can be 'frozen' and 'thawed' by the administrator.

The maximum size of message can be specified. Exim can handle a number of independent local domains on the same machine; each domain can have its own alias files, etc. These are commonly called

Exim stats a user's home directory before looking for a .forward file, in order to detect the case of a missing NFS mount.

Exim contains an optional built-in mail filtering facility. This enables users to set up their own mail filtering in a straightfoward manner without the need to run an external program. There can also be a system filter file that applies to all messages.

There is support for multiple user mailboxes controlled by prefixes or suffixes on the user name, either via the filter mechanism or through multiple .forward files.

Periodic warnings are automatically sent to messages' senders when delivery is delayed - the time between warnings is configurable.

A queue run can be manually started to deliver just a particular portion of the queue, or those messages with a recipient whose address contains a given string.

Exim can be configured to run as root all the time, except when performing local deliveries, which it always does in a separate process under an appropriate uid and gid. Alternatively, it can be configured to run as root only when needed; in particular, it need not run as root when receiving incoming messages or when sending out messages over SMTP.

I have tried to make the wording of delivery failure messages clearer and simpler, for the benefit of those less-experienced people who are now using email.

The Exim Monitor is an optional extra; it displays information about Exim's processing in an X window, and an administrator can perform a number of control actions from the window interface.

METHOD OF OPERATION

When Exim receives a message, it writes two files in its spool directory. The first contains the envelope information, the current status of the message, and the headers, while the second contains the body of the message. The status of the message includes a complete list of recipients and a list of those that have already received the message. The header file gets updated during the course of delivery if necessary.

A message remains in the spool directory until it is completely delivered to its recipients or to an error address, or until it is deleted by an administrator or by the user who originally created it. In cases when delivery cannot proceed - for example, when a message can neither be delivered to its recipients nor returned to its sender, the message is marked 'frozen' on the spool, and no more deliveries are attempted. The administrator can thaw such messages when the problem has been corrected, and can also freeze individual messages by hand if necessary.

As delivery proceeds, Exim writes timestamped information about each address to a per-message log file; this includes any delivery error messages. This log is solely for the benefit of the administrator. All the information Exim itself needs for delivery is kept in the header spool file. The message log file is deleted with the spool files. If a message is delayed for more than a configured time, a warning message is sent to the sender. This is repeated whenever the same time elapses again without delivery being complete.

The main delivery processing elements of Exim are called directors, routers, and transports. Code for a number of these is provided, and compile-time options specify which ones are actually included in the binary. Directors handle addresses that include one of the local domains, routers handle remote addresses, and transports do actual deliveries.

TRUSTED AND ADMIN USERS

Some Exim options are available only to

A trusted user is root or the Exim user (if defined) or any user listed in the trusted_users configuration option, or any user, if the currently set group is one of those listed in the trusted_groups configuration option. Trusted users are permitted to use the -f option to specify the senders of messages that are passed to Exim through the local interface, and also to specify host names, host addresses, protocol names, and ident values. Thus they are able to insert messages into Exim's queue locally that have the characteristics of messages received from a remote host.

An admin user is root or the Exim user (if defined) or any user that is a member of the Exim group (if defined). The current group does not have to be the Exim group. Admin users are permitted to operate on messages in the queue, for example, to force delivery failures. It is also necessary to be an admin user in order to see the full information provided by the Exim monitor.

OPTIONS

Exim's command options are as follows:

-bd

Run Exim as a daemon, awaiting incoming SMTP connections. This option can be used only by an admin user. If either of the -d or -dm options are set, the daemon does not disconnect from the controlling terminal. By default, Exim listens for incoming connections on all the host's interfaces, but it can be restricted to specific interfaces by setting the local_interfaces option in the configuration file. The standard SMTP port is used, but this can be varied by means of the -oX option. Most commonly, the -bd option is combined with the -q

The process id of a daemon that is both listening and starting queue runners is written to a file called exim-daemon.pid in Exim's spool directory, unless the -oX option is used, in which case the file name is exim-daemon.

It is possible to change the directory in which these pid files are written by changing the setting of PID_FILE_PATH in Local/Makefile. The files are written while Exim is still running as root. Further details are given in the comments in src/EDITME.

The SIGHUP signal can be used to cause the daemon to re-exec itself. This should be done whenever Exim's configuration file is changed, or a new version of Exim is installed. It is not necessary to do this when other files (e.g. alias files) are changed.

This option is the same as -bf except that it assumes that the filter

being tested is a system filter. The additional commands that are available only in system filters are recognized.

-bf

Run Exim in filter testing mode; the file is the filter file to be tested, and a test message must be supplied on the standard input. If there are no message-dependent tests in the filter, an empty file can be supplied. If a system filter file is being tested, -bF should be used instead of

  • bf. If the test file does not begin with the special

line

  1. Exim filter

then it is taken to be a normal .forward file, and is tested for validity under that interpretation. The result of this command, provided no errors are detected, is a list of the actions that Exim would try to take if presented with the message for real. More details of filter testing are given in the separate document entitled

When testing a filter file, the envelope sender can be set by the -f option, or by a 'From ' line at the start of the test message. Various parameters that would normally be taken from the envelope recipient address of a message can be set by means of additional command line options. These are:

  • bfd

The local part should always be set to the incoming address with any prefix or suffix stripped, because that is how it appears when a message is actually being delivered.

-bh

This option runs a fake SMTP session as if from the given IP address, using the standard input and output. Comments as to what is going on are written to the standard error file. These include lines beginning with 'LOG' for anything that would have been logged. This facility is for testing configuration options for blocking hosts and/or senders and for checking on relaying control. Messages supplied during the testing session are discarded, and nothing is written to any of the real log files. There may be pauses when DNS (and other) lookups are taking place, and of course these may time out. The -oMi option can be used to specify a specific IP interface if this is important.

-bi

Sendmail interprets the -bi option as a request to rebuild its alias file. Exim does not have the concept of a single alias file, and so it cannot mimic this behaviour. However, calls to /usr/lib/sendmail -bi tend to appear in various scripts such as NIS make files, so the option must be recognized.

If -bi is encountered, the command specified by the bi_command configuration option is run, under the uid and gid of the caller of Exim. If the -oA option is used, its value is passed to the command as an argument. The command set by bi_command may not contain arguments. The command can use the exim_dbmbuild utility, or some other means, to rebuild alias files if this is required. If the bi_command option is not set, then calling Exim with -bi is a no-op.

-bm

Accept an incoming, locally-generated message on the current input, and deliver it to the addresses given as the command arguments (except when -t is also given - see below). Each argument can be a comma-separated list of RFC 822 addresses. This is the default option, and is assumed if no other conflicting option is present.

The format of the message must be as defined in RFC 822, except that, for compatibility with sendmail and smail, a line in one of the forms

From sender Fri Jan 5 12:55 GMT 1999 From sender Fri, 5 Jan 97 12:55:01

(with the weekday optional, and possibly with additional text after the date) is permitted to appear at the start of the message. There appears to be no authoritative specification of the format of this line. Exim recognizes it by matching against the regular expression defined by the uucp_from_pattern option, which can be changed if necessary. The specified sender is treated as if it were given as the argument to the -f option, but if a -f option is also present, its argument is used in preference to the address taken from the message. The caller of Exim must be a trusted user for the sender of a message to be set in this way.

-bp

List the contents of the mail queue on the current output. If the -bp option is followed by a list of message ids, then just those messages are listed. By default this option may only be used by an admin user. The queue_list_requires_admin option can be set false to allow any user to see the queue.

Each message on the queue is displayed as in the following example:

25m 2.9K 0t5C6f-0000c8-00

The first line contains the amount of time the message has been on the queue (in this case 25 minutes), the size of the message (2.9K), the unique identifier for the message, and the message sender, as contained in the envelope. If the message is a delivery error message, the sender address is empty, and appears as

The recipients of the message (taken from the envelope, not the headers) are displayed on subsequent lines. Those addresses to which the message has already been delivered are marked with the letter D. If an original address gets expanded into several addresses via an alias or forward file, the original is displayed with a 'D' only when deliveries for all of its child addresses are completed.

-bpa

This option operates like -bp, but in addition it shows delivered addresses that were generated from the original top level address(es) in each message by alias or forwarding operations. These addresses are flagged with '+D' instead of just 'D'.

-bpr

This option operates like -bp, but the output is not sorted into chronological order of message arrival. This can speed it up when there are lots of messages on the queue, and is particularly useful if the output is going to be post-processed in a way that doesn't need the sorting.

-bpra

This option is a combination of -bpr and -bpa.

-bpru

This option is a combination of -bpr and -bpu.

-bpu

This option operates like -bp but shows only undelivered top-level addresses for each message displayed. Addresses generated by aliasing or forwarding are not shown, unless the message was deferred after processing by a director with the one_time option set.

-bP

If this option is given with no arguments, it causes the values of all Exim's main configuration options to be written to the standard output. The values of one or more specific options can be requested by giving their names as arguments, for example:

exim -bP qualify_domain local_domains

If configure_file is given, the name of the runtime configuration file is output. If log_file_path or pid_file_path are given, the names of the directories where log files and daemon pid files are written are output, respectively. If these values are unset, log files are written in a subdirectory of the spool directory called log, and pid files are written directly into the spool directory.

If one of the words director, router, or transport is given, followed by the name of an appropriate driver instance, the option settings for that driver are output. For example:

exim -bP transport local_delivery

The generic driver options are output first, followed by the driver's private options. A list of the names of drivers of a particular type can be obtained by using one of the words director_list, router_list, or transport_list, and a complete list of all drivers with their option settings can be obtained by using directors, routers, or transports.

-brt

This option is for testing retry rules, and it must be followed by up to three arguments. It causes Exim to look for a retry rule that matches the values and to output it on the standard output. For example:

exim -brt bach.comp.mus Retry rule: *.comp.mus F,2h,15m; FG,4d,30m;

See chapter 31 for a description of Exim's retry rules. The first argument, which is required, can be a complete address in the form local_part@domain, or it can be just a domain name. The second argument is an optional second domain name; if no retry rule is found for the first argument, the second is tried. This ties in with Exim's behaviour when looking for retry rules for remote hosts - if no rule is found that matches the host, one that matches the mail domain is sought. The final argument is the name of a specific delivery error, as used in setting up retry rules, for example 'quota_3d'.

-brw

This option is for testing address rewriting rules, and it must be followed by a single argument, consisting of either a local part without a domain, or a complete address with a fully-qualified domain. Exim outputs how this address would be rewritten for each possible place it might appear.

-bS

This option is used for batched SMTP input, where messages have been received from some external source by an alternative transport mechanism. It causes Exim to accept one or more messages by reading SMTP on the standard input, but to generate no responses. If any error is encountered reports are written to the standard output and error streams, and Exim gives up immediately.

If the caller is trusted, then the senders in the MAIL commands are believed; otherwise the sender is always the caller of Exim. Unqualified senders and receivers are not rejected (there seems little point) but instead just get qualified. Sender addresses are verified if sender_verify is set, unless sender_verify_batch is unset (which is the default). Receiver verification and administrative rejection is not done, even if configured. HELO and EHLO act as RSET; VRFY, EXPN, ETRN, HELP, and DEBUG act as NOOP; QUIT quits. The return code is 0 if no error was detected; it is 1 if one or more messages were accepted before the error was detected; otherwise it is 2. More details of input using batched SMTP are given in section 42.8.

-bs

This option causes Exim to accept one or more messages by reading SMTP commands on the standard input, and producing SMTP replies on the standard output. Some user agents use this interface as a way of passing locally-generated messages to the MTA. The option can also be used to run Exim from inetd, as an alternative to using a listening daemon, in which case the standard input is the connected socket. Exim distinguishes between the two cases by attempting to read the IP address of the peer connected to the standard input. If it is not a socket, the call to getpeername() fails, and Exim assumes it is dealing with a local message.

If the caller of Exim is trusted, then the senders of messages are taken from the SMTP MAIL FROM commands. Otherwise the content of these commands is ignored and the sender is set up as the calling user.

-bt

Run in address testing mode, in which each argument is taken as an address to be tested. The results are written to the standard output. If no arguments are given, Exim runs in an interactive manner, prompting with a right angle bracket for addresses to be tested. Each address is handled as if it were the recipient address on a message and passed to the appropriate directors or routers (compare the -bv option); the result is written to the standard output. The return code is 2 if any address failed outright; it is 1 if no address failed outright but at least one could not be resolved for some reason. Return code 0 is given only when all addresses succeed.

If any of the directors or routers in the configuration makes any tests on the sender address of a message, then you should use the -f option to set an appropriate sender when running -bt tests. Without it, the sender is assumed to be the calling user at the default qualifying domain.

-bV

Write the current version number, compilation number, and compilation date of the exim binary to the standard output.

-bv

Verify the addresses that are given as the arguments to the command, and write the results to the standard output. Verification differs from address testing (the -bt option) in that directors and routers that have no_verify set are skipped, and if the address is accepted by a director or router that has fail_verify set, verification fails. This is the same logic that is used when verifying addresses on incoming messages (see the sender_verify and receiver_verify options). The address is verified as a recipient if -bv is used; to verify as for a sender address, -bvs should be used.

If the -v (or -d) option is not set, the output consists of a single line for each address, stating whether it was verified or not, and giving a reason in the latter case. Otherwise, more details are given of how the address has been handled, and in the case of aliases or forwarding, the generated addresses are also considered.

The return code is 2 if any address failed outright; it is 1 if no address failed outright but at least one could not be resolved for some reason. Return code 0 is given only when all addresses succeed.

If any of the directors or routers in the configuration makes any tests on the sender address of a message, then you should use the -f option to set an appropriate sender when running -bv tests. Without it, the sender is assumed to be the calling user at the default qualifying domain.

-bvs

This option acts like -bv, but verifies the address as a sender rather than a recipient address. This affects any rewriting and qualification that might happen.

-C

Read the runtime configuration from the given file instead of from the default file specified by the CONFIGURE_FILE compile-time setting. When this option is used by an unprivileged caller, Exim gives up its root privilege immediately, and runs with the real and effective uid and gid set to those of the caller, to avoid any security exposure. It does not do this if the caller is root or the exim user. The facility is useful for ensuring that configuration files are syntactically correct, but cannot be used for test deliveries, unless the caller is privileged, or unless it's an exotic configuration that does not require privilege. No check is made on the owner or group of the file specified by this option.

-D

This option can be used to override macro definitions in the configuration file (see section 7.2). However, like -C, if it is used by an unprivileged caller, it causes Exim to give up its root privilege. This option may be repeated up to 10 times on a command line.

-d

Sets a debug level, causing debugging information to be written to the standard error file. Whitespace between -d and the number is optional. If no number is given, 1 is assumed, and the higher the number, the more output is produced. A value of zero turns debugging output off. A value of 9 gives the maximum amount of general information, 10 gives in addition details of the interpretation of filter files, and 11 or higher also turns on the debugging option for DNS lookups.

-df

If this option is set and STDERR_FILE was defined when Exim was built, debugging information is written to the file defined by that variable instead of to the standard error file. This option provides a way of obtaining debugging information when Exim is run from inetd.

-dm

This option causes information about memory allocation and freeing operations to be written to the standard error file.

-dropcr

At least one MUA (dtmail) that calls an MTA via the command line is broken in that it terminates each line with CRLF, instead of just LF, which is the usual Unix convention, and although this bug has been admitted, it apparently won't get fixed. There is also some UUCP software which leaves CR at the ends of lines in messages. As a slight pander to these programs, the -dropcr option causes Exim to drop all CR characters in an incoming non-SMTP message.

-ex

There are a number of sendmail options starting with -oe which seem to be called by various programs without the leading o in the option. For example, the vacation program uses -eq. Exim treats all options of the form -ex as synonymous with the corresponding -oex options.

-F

Set the sender's full name for use when a locally-generated message is being accepted. In the absence of this option, the user's

-f

Set the address of the sender of a locally-generated message. This option can normally be used only by root or the Exim user or by one of the configured trusted users. However, anyone may use it when testing a filter file with

  • bf or when testing or verifying addresses using the -bt or
  • bv options. In other cases, the sender of a local message

is always set up as the user who ran the exim command, and

  • f is ignored, with one exception. If the special setting -f

MAIL FROM:

and local deliveries to contain

Return-path:

when configured to contain Return-path: headers. The filtering code treats such a message as an error message, and won't generate messages as a result of reading it.

White space between -f and the

-h

This option is accepted for compatibility with sendmail, but at present has no effect. (In sendmail it overrides the 'hop count' obtained by counting Received headers.)

-i

This option, which has the same effect as -oi, specifies that a dot on a line by itself should not terminate an incoming, non-SMTP message. I can find no documentation for this option in Solaris 2.4 sendmail, but the mailx command in Solaris 2.4 uses it.

-M

The arguments are interpreted as a list of message ids, and Exim runs a delivery attempt on each message in turn. If any of the messages are frozen, they are automatically thawed before the delivery attempt. Retry hints for any of the addresses are overridden - this option forces Exim to try to deliver even if the normal retry time has not yet been reached. This option requires the caller to be an admin user. However, there is an option called prod_requires_admin which can be set false to relax this restriction (and also the same requirement for the -q and -R options).

-Mar

The first argument must be a message id, and the remaining ones must be email addresses. Exim adds the addresses to the list of recipients of the message. However, if the message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user.

-Mc

The arguments are interpreted as a list of message ids, and Exim runs a delivery attempt on each message in turn, but unlike the -M option, it does check for retry hints, and respects any that are found. This option is not very useful to external callers (except for testing). It is provided for internal use by Exim when it needs to re-invoke itself in order to regain root privilege for a delivery (see chapter 49).

-Meb

This runs, under /bin/sh, the command defined in the shell variable VISUAL or, if that is not defined, EDITOR or, if that is not defined, the command vi, on a copy of the spool file containing the body of message (eb = Edit Body). If the editor exits normally, then the result of editing replaces the spool file. The message is locked during this process, so no delivery attempts can occur. Note that the first line of the spool file is its own name; care should be taken not to disturb this. The thinking behind providing this feature is that an administrator who has had to mess around with the addresses to get a message delivered might want to add some (grumbly) comment at the start of the message text. This option can be used only by an admin user.

-Mes

There must be exactly two arguments. The first argument must be a message id, and the second one an email address. Exim changes the sender address in the message to the given address, which must be a fully qualified address, or '

-Mf

The arguments are interpreted as a list of message ids, and each message is marked 'frozen'. This prevents any delivery attempts taking place until the message is 'thawed', either manually or as a result of the auto_thaw configuration option. However, if any of the messages are active (in the middle of a delivery attempt), their status is not altered. This option can be used only by an admin user.

-Mg

The arguments are interpreted as a list of message ids, and Exim gives up trying to deliver those messages. A delivery error message is sent, containing the text 'cancelled by administrator'. However, if any of the messages are active, their status is not altered. This option can be used only by an admin user.

-Mmad

Exim marks the all recipient addresses in the message as already delivered. However, if the message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user.

-Mmd

The first argument must be a message id, and the remaining ones must be email addresses. Exim marks the given addresses as already delivered. However, if the message is active (in the middle of a delivery attempt), its status is not altered. This option can be used only by an admin user.

-Mrm

The arguments are interpreted as a list of message ids, and each message is completely removed from Exim's queue, and forgotten. However, if any of the messages is active, its status is not altered. This option can be used only by an admin user or by the user who originally caused the message to be placed on the queue.

-Mt

The arguments are interpreted as a list of message ids, and each message that was 'frozen' is now 'thawed', so that delivery attempts can resume. However, if any of the messages is active, its status is not altered. This option can be used only by an admin user.

-Mvb

The contents of the message body (-D) spool file are written to the standard output. This option can be used only by an admin user.

-Mvh

The contents of the message headers (-H) spool file are written to the standard output. This option can be used only by an admin user.

-Mvl

The contents of the message log spool file are written to the standard output. This option can be used only by an admin user.

-m

This is apparently a synonym for -om that is accepted by sendmail, so Exim treats it that way too.

-N

This is a debugging option that inhibits delivery of a message at the transport level. It implies at least -d1. Exim goes through many of the motions of delivery - it just doesn't actually transport the message, but instead behaves as if it had successfully done so. However, it does not make any updates to the retry database, and the log entries for deliveries are flagged with '*

-oA

This option is used by Sendmail in conjunction with -bi to specify an alternative alias file name. Exim handles -bi differently; see the description above.

-oB

This is a debugging option which limits the maximum number of SMTP deliveries down one channel to

-odb

This option applies to all modes in which Exim accepts incoming messages, including the listening daemon. It requests 'background' delivery of such messages, which means that the accepting process automatically starts another delivery process for each message received. Exim does not wait for such processes to complete (it can take some time to perform SMTP deliveries). This is the default action if none of the -od options are present.

-odf

This option (compatible with smail) requests 'foreground' (synchronous) delivery when Exim has accepted a locally-generated message. For the daemon it is exactly the same as -odb. For a single message received on the standard input, if the protection regime permits it (see chapter 44), Exim converts the reception process into a delivery process. In other cases, it creates a new delivery process, and then waits for it to complete before proceeding.

-odi

This option is synonymous with -odf. It is provided for compatibility with sendmail.

-odq

This option applies to all modes in which Exim accepts incoming messages, including the listening daemon. It specifies that the accepting process should not automatically start a delivery attempt for each message received. Messages are placed on the queue, and remain there until a subsequent queue-running process encounters them. The queue_only configuration option has the same effect.

-odqr

This option applies to all modes in which Exim accepts incoming messages, including the listening daemon. It causes Exim to process local addresses when a message is received, but not even to try routing remote addresses. Contrast with

  • odqs below, which does the routing, but not the delivery.

The remote addresses will be picked up by the next queue runner. The queue_remote configuration option has the same effect for specific domains.

-odqs

This option is a hybrid between -odb and -odq. A delivery process is started for each incoming message, the addresses are all processed, and local deliveries are done in the normal way. However, if any SMTP deliveries are required, they are not done at this time. Such messages remain on the queue until a subsequent queue-running process encounters them. Because routing was done, Exim knows which messages are waiting for which hosts, and so a number of messages for the same host will get sent in a single SMTP connection. The queue_smtp configuration option has the same effect for specific domains. See also the -qq option.

-oee

If an error is detected while a non-SMTP message is being received (for example, a malformed address), the error is reported to the sender in a mail message. Provided the message is successfully sent, Exim exits with a return code of zero. If not, the return code is 2 if the error was that the message had no recipients, and 1 otherwise. This option is the default if Exim is called as rmail.

-oem

This is the same as -oee, except that Exim always exits with a non-zero return code, whether or not the error message was successfully sent. This is the default option, unless Exim is called as rmail.

-oep

If an error is detected while a non-SMTP message is being received, the error is reported by writing a message to the standard error file (stderr).

-oeq

This option is supported for compatibility with sendmail, but has the same effect as -oep.

-oew

This option is supported for compatibility with sendmail, but has the same effect as -oem.

-oi

This option, which has the same effect as -i, specifies that a dot on a line by itself should not terminate an incoming, non-SMTP message. This is the default if Exim is called as rmail.

-oMa

This option sets the sender host address value, and can be used only by a trusted caller, except in conjunction with the -bh option. A real incoming connection overrides the address set by -oMa.. The value is used in log entries and can appear in Received: headers. The option is intended for use when handing to Exim messages received by other means, either via the command line or by using the -bs option. If

  • oMt is set then -oMa should normally be set as

well.

-oMi

This option sets the IP interface address value, and can be used only by a trusted caller, except in conjunction with the -bh option. A real incoming connection overrides the address set by -oMi. The option is intended for use when handing to Exim messages received by other means, either via the command line or by using the -bs option.

-oMr

This option sets the received protocol value, and can be used only by a trusted caller, except in conjunction with the -bh option. The value is used in log entries and can appear in Received: headers. The option is intended for use when handing to Exim messages received by other means. It applies only to non-SMTP and batched SMTP input.

-oMs

This option sets the sender host name value, and can be used only by a trusted caller, except in conjunction with the -bh option. The value is used in log entries and can appear in Received headers. The option is intended for use when handing to Exim messages received by other means.

-oMt

This option sets the sender ident value, and can be used only by a trusted caller, except in conjunction with the -bh option. The value is used in log entries and can appear in Received headers. The default setting for local callers is the login id of the calling process. This can be overridden by supplying an empty argument. The option is intended for use when handing to Exim messages received by other means.

-om

In sendmail, this option means 'me too', indicating that the sender of a message should receive a copy of the message if the sender appears in an alias expansion. Exim always does this, so the option does nothing.

-or

This option sets a timeout value for incoming non-SMTP messages. If it is not set, Exim will wait forever for the standard input. The value can also be set using the accept_timeout configuration vari- able. The format used for specifying times is described in section 7.7.

This option has exactly the same effect as -v.

-oX

This option is relevant only when the -bd option is also given. It overrides any setting of the daemon_smtp_port option, and specifies an alternative TCP/IP port number for the listening daemon. When used, the process number of the daemon is written to a file whose name is exim-daemon.

-pd

This option applies when an embedded Perl interpreter is linked with Exim (see chapter 10). It therefore does not apply to the debian package.

It overrides the setting of the perl_at_start option, forcing the starting of the interpreter to be delayed until it is needed.

-ps

This option applies when an embedded Perl interpreter is linked with Exim (see chapter 10). It therefore does not apply to the debian package.

It overrides the setting of the perl_at_start option, forcing the starting of the interpreter to occur as soon as Exim is started.

-q

If the -q option is not followed by a time value, it requests a single queue run operation. This option can be used only by an admin user. However, there is an option called prod_requires_admin which can be set false to relax this restriction (and also the same requirement for the -M and R options).

Exim starts up a delivery process for each (inactive) message on the queue in turn, and waits for it to finish before starting the next one. If the delivery process spawns other processes to deliver other messages down passed SMTP connections, the queue runner waits for these to finish before proceeding. When all the queued messages have been considered, the original process terminates. In other words, a single pass is made over the waiting mail. Use -q with a time (see below) if you want this to be repeated periodically.

Exim processes the waiting messages in an unpredictable order. It isn't very random, but it is likely to be different each time, which is all that matters. If one particular message screws up a remote MTA, other messages to the same MTA have a chance of getting through if they get tried first.

However, it is possible to cause the messages to be processed in lexical id order, which is essentially the order in which they arrived, and to start this operation at a particular point by following the -q option with a starting message id. For example:

exim -q 0t5C6f-0000c8-00

This causes Exim to skip any messages whose ids are lexically less than the given id. A second id can also be given to stop the queue run before the end. See also the -R option and the queue_run_in_order option.

-q

This version of the -q option (which again can be run only by an admin user) causes Exim to run as a daemon, starting a queue-running process at intervals specified by the given time value (whose format is described in section 7.6). This form of the -q option is commonly combined with the -bd option, in which case a single daemon process handles both functions. A common way of starting up a combined daemon at system boot time is to use a command such as

/opt/exim/bin/exim -bd -q30m

Such a daemon listens for incoming SMTP calls, and also fires up a queue-runner process every 30 minutes. The process id of such a daemon is written to a file called exim-daemon.pid in Exim's spool directory, unless the -oX option has been used, in which case the file is called exim-daemon.

-qf

This option operates like -q, and may appear with or without a following time. The difference is that a delivery attempt is forced for each message, whereas with -q only those addresses that have passed their retry times are tried.

-qff

This option operates like -qf and may appear with or without a following time. The difference is that any frozen messages are automatically thawed, and delivery is attempted for them.

-qfl

This option operates like -ql, and may appear with or without a following time. The difference is that a delivery attempt is forced for each message, whereas with -ql only those local addresses that have passed their retry times are tried.

-qffl

This option operates like -qfl and may appear with or without a following time. The difference is that any frozen messages are auto-matically thawed, and delivery is attempted for any local addresses in them.

-ql

This option operates like -q, and may appear with or without a following time. The difference is that only local addresses are considered for delivery. Note that -ql cannot detect apparently remote addresses that actually turn out to be local when their domains get fully qualified.

-qq...

If any command line option starting with -q is specified with an additional q (for example, -qqf) then all the resulting queue runs are done in two stages. In the first stage, the queue is scanned as if the queue_smtp_domains option matched every domain. This causes remote addresses to be routed, but no transportation to be done. The database that remembers which messages are waiting for specific hosts is updated, as if delivery to those hosts had been deferred. After this is complete, a second, normal queue scan happens, and normal directing, routing, and delivery takes place. Messages which are routed to the same host should mostly be delivered down a single SMTP connection because of the hints that were set up during the first queue scan. This option may be useful for hosts that are connected to the Internet intermittently.

-qR

This option is synonymous with -R. It is provided for sendmail compatibility.

-qRf

This option is synonymous with -Rf.

-R

The white space between -R and the string is optional. This option is similar to -q with no time value, except that, when scanning the messages on the queue, Exim processes only those that have at least one undelivered address containing the given string, which is checked in a case-independent way. However, once a message is selected, all its addresses are processed. For the first message containing a matching address, Exim overrides any retry information and forces a delivery attempt. This makes it straightforward to initiate delivery for all messages to a given domain after a host has been down for some time. When the SMTP command ETRN is permitted (see the smtp_etrn options), its effect is to run Exim with the -R option.

-Rf

This option acts like -R, but forces a delivery for every matching non-frozen message, not just the first one. White space is required between -Rf and the string.

-Rff

This option acts like -Rf, but also thaws any frozen messages it encounters.

-r

This is a documented (for sendmail) obsolete alternative name for -f.

-t

When Exim is receiving a locally-generated, non-SMTP message on the current input, the -t option causes the recipients of the message to be obtained from the To:, Cc:, and Bcc: headers in the message instead of from the command arguments. The addresses are extracted before any rewriting takes places.

If there are in fact any arguments, they specify addresses to which the message is not to be delivered. That is, the argument addresses are removed from the recipients list obtained from the headers. This is compatible with Smail 3 and in accordance with the documented behaviour of Sendmail. However, it has been reported that in some versions at least, Sendmail adds argument addresses to those obtained from the headers. Exim can be made to behave in this way by setting the option extract_addresses_remove_arguments false.

If a Bcc: header is present, it is removed from the message unless there is no To: or Cc: header, in which case a Bcc: header with no data is created, in accordance with RFC 822.

-v

This option has exactly the same effect as -d1; it causes Exim to be standard error file. In particular, if an SMTP connection is made, the SMTP dialogue is shown.

-x

AIX uses -x for a private purpose ('mail from a local mail program has National Language Support extended characters in the body of the mail item'). It sets -x when calling the MTA from its mail command. Exim ignores this option.

SEE ALSO

There is extensive documentation available in /usr/share/doc/exim and in the info system regarding exim. Debian users please be sure to have the exim-doc package installed.

AUTHOR

This manual page was stitched together by Christoph Lameter,


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