Provided by: courier-mlm_1.0.6-1_amd64 bug

NAME

       couriermlm - The Courier mailing list manager

SYNOPSIS

       couriermlm {command} {directory} [arg...]

DESCRIPTION

       couriermlm is the Courier mail server's mailing list manager. This command sets up,
       maintains, and manages mailing lists.  couriermlm automatically handles requests to
       subscribe and unsubscribe list members, detects undeliverable addresses and removes them
       from the subscription rolls. Mailing lists managed by couriermlm require zero human
       administrative oversight.  couriermlm supports digests, write-only posting aliases, and
       moderated mailing lists.

   CREATING A MAILING LIST
       Anyone can use couriermlm, not just the system administrator. The Courier mail server mail
       server translates an address list-name@domain as a local address with a corresponding dot-
       courier(5)[1] file. Anyone that can install a dot-courier(5)[1] file, and can schedule
       cron(8) jobs, can run a couriermlm mailing list.

       Note that the system administrator can optionally remove the dot-courier(5)[1] support
       from the the Courier mail server.  couriermlm will not work in that case.

       Setting up a mailing list consists of the following steps:

       Run couriermlm create
           Use this command to create a directory where couriermlm keeps all mailing list related
           files.

       Configure the mailing list
           The couriermlm create command initializes the mailing list subdirectory with some
           default template responses. It is necessary to customize them for your mailing list,
           and it may be necessary to issue some additional commands in order to configure
           appropriate mailing list options -- such as enabling unrestricted posting privileges,
           and enabling moderation.

       Create dot-courier(5)[1] files
           Set up to run couriermlm to distribute mailing list messages, and process requests.

       Set up cron(8)
           You need to set up cron(8) jobs to run the couriermlm hourly and couriermlm daily
           commands, which perform regular mailing list maintenance.

       Enable SMTP pre-filtering
           This step configures a hook that runs couriermlm as part of the SMTP transaction when
           receiving mail to a mailing list address, and rejects the mail if it would not be
           accepted to the mailing list instead of receiving the message and then generating a
           non-delivery report.

           This is an optional step that adds some complexity, but reduces mailing list
           management issues.

       Back up subscription lists
           As part of your daily job you should also run the export command, in order to back up
           the mailing list subscriber information. In the event that the mailing list database
           gets corrupted or lost, you can restore it from this backup file. See the export
           command for more information.

           Note
           Setting up a digest for the mailing list requires additional steps. See "Setting up a
           mailing list digest[2]" below for more information.

       The first step is to run the following command:

           couriermlm create directory ADDRESS=list@domain

       directory is the mailing list directory that will be managed by couriermlm. This directory
       should not be created in advance, this command creates this directory, and initializes it.

       list@domain is the mailing list's address, the address that sends messages to the mailing
       list.

       An additional setting, URL may also be specified:

           couriermlm create directory ADDRESS=list@domain URL=url

       “url” would be the URL of the WebMLM web page for this mailing list. See webmlmd(1)[3] for
       more information.

       The directory created by couriermlm create is initialized to contain a number of text
       files that couriermlm sends back as replies to administrative commands. It is necessary to
       edit these template files and adjust the text in those files for this mailing list. All
       template filenames end with .tmpl, and their contents are self explanatory. Some important
       template files are:

       help.tmpl
           This text is returned in response to the help command. This text must be modified
           depending upon whether this mailing list is a moderated mailing list, has a digest
           version, or if any other non-default configuration options are set for the mailing
           list.

       sub.tmpl
           This is the reply that's sent back in response to a subscription request. Less
           important is unsub.tmpl, which is the response to a request to unsubscribe.

       sub2.tmpl
           This is the successful subscription confirmation. A brief overview of the mailing list
           might be appropriate here.

       couriermlm has rudimentary support for non-English templates. The couriermlm create
       command has a single, optional parameter, --lang=suffix The option must be specified after
       the mailing list directory's name:

           couriermlm create directory --lang=es ADDRESS=list@domain URL=url

       The templates for the stock text files come from /usr/lib/courier/couriermlm. This
       directory contains all the *.tmpl and *.html template files that couriermlm create
       installs in the new mailing list directory.

       Translated versions of template files are installed in the same directory,
       /usr/lib/courier/couriermlm. The translated version of file must be installed as
       file.suffix, for example: help.tmpl.es is the translated version of help.tmpl, with the
       “es” suffix.

       The --lang=suffix option installs the the .suffix version of each text template file, if
       available. If not, the stock English template file gets copied, as usual.

           Note
           Do not remove the English template files, even if you never use them. They must be
           left in place, in /usr/lib/courier/couriermlm, for couriermlm create to work
           correctly.

       Example:

           couriermlm create /home/lists/users-list --lang=es ...

       This example installs the *.es versions of mailing list template files. Only the stock,
       English template files come with the Courier mail server. This mechanism only provides an
       easy integration ability with template files from other sources.

       There are some additional configuration files that can be modified to suit your taste:

       headeradd
           This file can be initialized to contain any mail headers that will be automatically
           added to every mailing list message. The contents of this file are simply prepended to
           every message that goes out. Blank lines are not allowed.

       headerdel
           This file lists any headers that will be automatically removed from every mailing list
           message before it's sent. List each header one per line, including the : character.
           For example, to remove all Received: and Date: headers from every message, initialize
           this file to contain the following two lines:

               Received:
               Date:

       Both the headeradd and headerdel files can be used to implement a popular feature of
       setting the replies to every message to go to the mailing list. Having "Reply-To:" in
       headerdel, removes any existing Reply-To: header, and then having "Reply-To: list@domain"
       in headeradd appends a fixed Reply-To: header to every message.

       The create command also creates the following subdirectories in the mailing list
       directory:

       sublist
           This subdirectory has the database files that contain the mailing list's subscription
           list.

       unsublist
           This subdirectory stores files that contain information about addresses that have been
           unsubscribed from the mailing list. This information might be of some use when
           tracking down an old subscription. The contents of this directory are not
           automatically purged, you must set up your own purging mechanism for this directory.

       commands, commands.dat
           These directories store temporary files that contain pending (unconfirmed) commands
           for the mailing list manager. The couriermlm commands hourly and daily must be
           executed regularly in order to periodically purge stale entries.

       modqueue
           Messages awaiting moderator approval (for moderated lists).

       archive
           Messages received by this mailing list will be stored here, in addition to being
           forwarded to subscribers.  couriermlm does not automatically do any purging on this
           subdirectory, you must set up your own archiving mechanism that cleans out this
           subdirectory.

       The last step involves installing a couple of dot-courier(5)[1] files that run couriermlm
       to receive mailing list messages and administrative commands. The mailing list address,
       list@domain, corresponds to some dot-courier(5)[1] file. For example, if your system
       account is john, and your mail domain is example.com, then the dot-courier(5)[1] file for
       the mailing list <john-list@example.com> is $HOME/.courier-list.

       Let's say that the dot-courier(5)[1] file is $HOME/.courier-list. To properly support the
       mailing list, the following dot-courier(5)[1] files will have to be initialized as
       follows:

       $HOME/.courier-list
           This file should be initialized to contain the following delivery instruction:

               | /usr/bin/couriermlm msg directory

           directory is the created mailing list directory.

               Note
               Messages to “POST=subscribers” lists from non-subscribers get rejected by
               couriermlm resulting in delivery failure. This generates a undeliverable message
               report, a “bounce”. Unfortunately this can be abused to generate a bandwidth
               amplification attack. Append "; exit 0" to the .courier command, to suppress
               bounces from delivery failures:

                   | /usr/bin/couriermlm msg directory; exit 0

               This will suppress all bounces, though, not just the ones resulting from messages
               from non-subscribers. A better solution is to configure SMTP pre-filtering, as
               described below. SMTP pre-filtering checks each message before it's accepted from
               the sending SMTP server. A rejected message does not generate a bounce message,
               but returns an error to the sending SMTP server, leaving it on the hook for
               generating bounces.

       $HOME/.courier-list-owner
           This file should contain the appropriate delivery instructions for forwarding all mail
           addressed to <list-owner@domain> to the address of the owner of the mailing list. This
           can be another E-mail address, or a mailbox specification.

       $HOME/.courier-list-default
           This file should be initialized to contain the following delivery instruction:

               | /usr/bin/couriermlm ctlmsg directory

           directory is the created mailing list directory. This dot-courier(5)[1] file provides
           support for all other addresses of the form <list-command@domain>, where command is a
           mailing list administrative command. Commands are sent to this mailing list manager by
           sending a message to one of several special addresses, described more fully in
           "Mailing list commands[4]", below.

   Configuring SMTP pre-filtering of mailing list messages
       This is an optional step that implements filtering of mailing list messages before each
       message is received from the sending SMTP server. Otherwise, Courier accepts all messages,
       and the rejected ones generate a non-delivery report. The report gets E-mailed to the
       purported sender. Another option is to quietly ignore the rejections, as described above.
       Either way, non-delivery notifications can sometimes be problematic. This step adds some
       complexity to the mailing list configuration, but mostly eliminates this problem.

       SMTP pre-filtering uses the localmailfilter(7)[5] interface. The following instructions
       repeat some of the information from the localmailfilter(7) documentation, for convenience.
       See that documentation for complete information.

       The following instructions reference a typical mailing list configuration setup:

       ·   A reserved system account called “lists”.

       ·   A mailing list's address of “lists-announcements@example.com”, set up by installing
           $HOME/.courier-announcements and $HOME/.courier-announcements-default (and
           $HOME/.courier-announcements-owner) in lists's home directory, as described above.

       ·   The mailing list directory (created by couriermlm create) is $HOME/announcements.

       The first two steps enable SMTP mail filtering using maildrop, and this should be done as
       root:

           # echo /usr/bin/maildrop >/etc/courier/maildropfilter

           Note
           This enables SMTP mail filtering to all local mailboxes. All local mailboxes will be
           able to specify their SMTP mail filters, as explained in localmailfilter(7).

       The second step installs couriermlm wrappers for SMTP filters:

           # mkdir /etc/courier/maildroprcs
           # d="/usr/lib/courier/couriermlm"
           # ln -s $d/couriermlm-rcptfilter-ctlmsg /etc/courier/maildroprcs
           # ln -s $d/couriermlm-rcptfilter-msg /etc/courier/maildroprcs
           # ln -s $d/couriermlm-smtpfilter-ctlmsg /etc/courier/maildroprcs
           # ln -s $d/couriermlm-smtpfilter-msg /etc/courier/maildroprcs

       The remaining steps are done while logged in as the mailing list owner's account:

           $ mkdir $HOME/.mailfilters
           $ chmod 700 $HOME/.mailfilters

       Each mailing list needs four maildrop scripts installed in .mailfilters. Using the
       “lists-announcements@example.com” list as an example, owned by lists's account:

           $ cd $HOME/.mailfilters
           $ cat rcptfilter-announcements

           LISTDIR="announcements"
           include '/etc/courier/maildroprcs/couriermlm-rcptfilter-msg'

           $ cat rcptfilter-announcements-default

           LISTDIR="announcements"
           FILENAMEPREFIX="rcptfilter-announcements"
           include '/etc/courier/maildroprcs/couriermlm-rcptfilter-ctlmsg'

           $ cat smtpfilter-announcements

           LISTDIR="announcements"
           include '/etc/courier/maildroprcs/couriermlm-smtpfilter-msg'

           $ cat smtpfilter-announcements-default

           LISTDIR="announcements"
           FILENAMEPREFIX="smtpfilter-announcements"
           include '/etc/courier/maildroprcs/couriermlm-smtpfilter-ctlmsg'

       And the permissions must be nailed down, as always:

           $ chmod 600 $HOME/.mailfilters/*

       Each maildrop script sets the LISTDIR variable before invoking the couriermlm wrapper.
       LISTDIR is the name of the mailing list's directory, in the account's home directory. In
       this case the mailing list directory, created by couriermlm create is $HOME/announcements,
       so LISTDIR is announcements. It's possible to put mailing list directories in a
       subdirectory, and reference the subdirectory here. Mailing list directories' names cannot
       contain periods.

       Additionally, the two -default scripts must set FILENAMEPREFIX to their own names, with
       the “-default” suffix stripped off.

       The easiest way to test this configuration is to use the default mailing list
       configuration that allows messages only from the list's subscribers, then attempt to send
       a message to the mailing list, from another SMTP server, using a return address that's not
       subscribed to the list. The resulting non-delivery report should come from the other SMTP
       server, and not couriermlm's mail server.

   MANUAL COMMANDS
       couriermlm may also be run manually from the command line as follows:

           /usr/bin/couriermlm command directory [ options... ]

       command is a command from the following list.  directory is the mailing list directory.
       The commands are:

       create
           Create a mailing list.

       update
           Update/restore mailing list templates. The original, default, mailing list message
           template files (*.tmpl and *.tmpl.html) are reinstalled into the mailing list
           directory. This command must be processed for every mailing list directory after
           upgrading to the Courier server version 0.55, or later, from earlier versions (but see
           below).  couriermlm in version 0.55 of the Courier mail server uses updated templates
           files, which must be installed in every mailing list directory. Although the names of
           many template files have not changed, the embedded markup codes in the template files
           work differently.

            1. Begin by making a backup copy of all *.tmpl files in the existing couriermlm
               mailing list directory.

            2. Run the “update” command on the list directory.

            3. Review the backed up template files, identify your customized changes, then retype
               them into new template files installed by the “update” command.

            4. Proceed to the next mailing list directory.

           Yes, this is going to be a pain. This is the first overhaul of couriermlm's
           infrastructure in many years. Once a decade, some elbow grease must be sacrificed in
           the name of progress. It's not the end of the world.

           In an extreme emergency, preserve the couriermlm from the previous version of the
           Courier mail server. Mass-update all existing lists' .courier-list and
           .courier-list-default files to run the old couriermlm. Then, migrate each mailing list
           on a predetermined schedule. After migrating each list, put the default path back into
           the list's .courier files.

           Keep in mind the following issues, while migrating the lists:

           ·   The help.tmpl template file is usually the one that gets customized the most. In
               most cases, large bits and pieces of this file, that document certain list options
               that do not apply to this list, must be removed.

           ·   There are several new template files, including a number of *.html files that
               refer to new HTML-formatted responses from couriermlm, and the WebMLM interface.

           ·   Be aware of updated mail headers declared in several template files. The MIME
               character set is now given as utf-8. Some templates no longer contain the
               Mime-Version and Subject headers. The Subject headers are moved to separate
               template files. Many existing template files now contain both a plain text and an
               HTML-formatted version of the couriermlm response. Always scroll to the end of
               each template file, to reveal any appended HTML portion of template's text.

       set
           Set mailing list options, see below.

       sub
           Manually subscribe an address to the mailing list.

       unsub
           Manually unsubscribe an address from the mailing list.

       lsub
           List all the subscribers to this mailing list.

       laliases
           List write-only aliases for this mailing list.

       export
           Export mailing list subscriber information.

       import
           Import mailing list subscriber information.

       ctlmsg
           Receive and interpret a control message.

       info
           Display a subscription record.

       msg
           Post a message to the mailing list.

       hourly
           Perform hourly maintenance. It is necessary to set up a cron(8) job to execute the
           hourly command once an hour.

       daily
           Perform daily maintenance. It is necessary to set up a cron(8) job to execute the
           daily command once a day.

       digest
           Create a digest. See "Setting up a mailing list digest[2]" below for more information.

   MANUAL SUBSCRIPTION MANAGEMENT
       The sub, unsub, lsub, laliases, export, and import commands allow manual subscription list
       management. Normally, subscription-related commands are done by sending an appropriate
       mailing list command, see "Mailing List Commands[4]", below.

           couriermlm sub directory user@domain

       This command adds the address <user@domain> to the subscription list.  couriermlm will now
       read a free-form comment or a note from standard input, terminated by an end-of-file
       (usually CTRL-D). The free-form comment is stored in the subscription database, together
       with the address, and is shown by the "info" command.

           couriermlm unsub directory user@domain

       This command remove the address <user@domain> from the subscription rolls.  couriermlm
       will also read a free-form comment, which is added to the subscription record. After
       removing this address from the subscription rolls, its subscription record is archived in
       the directory/unsublist directory.

           couriermlm lsub directory

       This command lists all the addresses subscribed to the list, on standard output, one per
       line.

           couriermlm laliases directory

       This command lists all write-only aliases that have been subscribed to the list, together
       with the subscriber address that added each alias. See "Write-Only Aliases[6]" for more
       information.

           couriermlm export directory

       The export command lists the contents of the subscription database on standard output. The
       export command produces the following output format:

           address
           subscription information
            ...
           address
           subscription information
            ...

       "address", is an address subscribed to the mailing list. This is followed by its
       corresponding subscription information, usually a copy of the subscription request that
       was used to add the address to the mailing list. The subscription information is
       terminated by a line containing a single period. Any lines in the subscription information
       that begin with a period have an extra period prepended to them.

           couriermlm import directory

       The import command reads on standard input a previously exported mailing list subscription
       database, and adds those addresses to the indicated mailing list.

       It is highly recommended to make a regular backup of subscriber information using the
       export command, in the event that the subscription database gets corrupted. In which case
       the import command can be used to rebuild the subscription database, in absence of any
       direct backups of the database files.

   SETTING MAILING LIST OPTIONS
       The set command sets various list options:

           couriermlm set directory option=value option=value...

           Note
           Setting the ADDRESS or the URL options, described below, automatically updates the
           contents of the headeradd configuration file. Its existing “List-” headers are removed
           and replaced by updated “List-” headers that reflect the revised list address or URL.

       One or more options can be set with the same command. The available options are:

       ADDRESS=address
           The base E-mail address for this mailing list.

       URL=address
           The URL of WebMLM web page for this mailing list.

               Note
               WebMLM determines its own URL automatically, by reading its HTTP headers. This
               setting is used by couriermlm, which has no knowledge of the web server's
               configuration, and needs to know the correct URL to insert into generated
               messages.

       CASESENSITIVE=flag
           If flag is "1", the userid portion of E-mail addresses are case-sensitive. The domain
           address portion is always case-insensitive. The default setting is "0" making both
           userid and domain address portions of E-mail addresses case-insensitive.

               Note
               Be careful when changing this setting on an active list. Changing this option to
               “CASESENSITIVE=1”, forces all existing subscribers to make sure their addresses
               are lowercase-only, otherwise they will no longer be recognized as subscribers.
               Changing this option to “CASESENSITIVE=0” blocks all subscribed addresses that
               have uppercase characters in the userid portion of their E-mail address. They will
               continue to receive mailing list traffic, but unable to post messages to the list,
               or unsubscribe from it. It will not be possible to unsubscribe those addresses
               even by running the couriermlm command manually.

       DIGEST=directory
           Enable digests.  directory is the pathname to the previously-createddigest list
           directory. See "Setting up a mailing list digest[2]" below for more information.

       KEYWORD=keyword
           Set the subject line keyword for mailing list messages. If set, couriermlm inserts
           "[keyword]" into the subject of every mailing list message, to aid sorting by the
           recipients.

       MAXBOUNCES=n
           Maximum number of bounce notifications sent by the hourly command, in order to prevent
           the mail system from being overloaded. The default is 20 bounce notifications. Any
           unsent notifications will be carried over to the next hourly job.

       MAXMODNOTICES=n
           Maximum number of moderation reminders sent by the hourly command, in order to prevent
           the mail system from being overloaded. The default is 20 moderation reminders. Any
           unsent reminders will be carried over to the next hourly job.

       MAXFETCHSIZE=K
           Maximum size, in kilobytes, of a response to the fetch command. The default is 100Kb.
           This option is used to minimize the impact of abusive requests for the entire archive,
           with a forged return address.

       NAME=name
           The name that's listed on the return address of administrative messages. Note that if
           name contains spaces, you should quote this argument in the shell. The default value
           is "Courier Mailing List Manager".

       NOBOZOS=flag
           If flag is "0" couriermlm will not attempt to block misdirected subscribes and
           unsubscribes that are sent to the mailing list's posting address. If flag is "1" (the
           default), those kinds of messages will be bounced appropriately.

       NODSN=flag
           If flag is "1" couriermlm will use a Delivery Status Notification setting of "never"
           when it sends confirmation requests and help messages: this should reduce the amount
           of useless failure notifications generated when couriermlm dutifully replies to spam
           received by the mailing list administrative addresses, i.e. -(un)subscribe and -help.
           If flag is "0" (the default), a DSN setting of "fail" will be used. Please see
           sendmail(1)'s -n option for more details on the DSN setting.

       POST=option
           Set posting options.  option is one of three values: "subscribers" - only subscribers
           may post messages to this mailing list (this is the default); "all" - anyone can post
           messages to this mailing list; "mod" - only subscribers may post, and messages are
           sent to the list owner for approval (moderation).

       UNICODE=flag
           Accept mailing list messages with Unicode-formatted headers. The default setting of 0
           rejects messages with Unicode headers, and rejects subscription requests from E-mail
           addresses with Unicode mailbox names.

           Most mail servers on the Internet do not implement support for Unicode messages at
           this time. Accepting a Unicode message and redistributing it to a mailing list results
           in delivery failures to all mailing list subscribers that do not implement Unicode
           support, so by default this setting is turned off. Set UNICODE to 1 to accept mailing
           list messages with Unicode headers, and subscription requests from Unicode mailbox
           names.

               Note
               Subscription requests from E-mail addresses that have an international domain name
               are always accepted if the internal domain name uses ASCII-compatible encoding.

       POSTARCHIVE=option
           Set access to archived messages.  option is either: "all" - Anyone can access the
           mailing list archive; or "subscribers" - only subscribers can access the archive. The
           default is "all".

       PURGEARCHIVE=d
           Purge archived mailing list messages after d days. The default is 0 days - messages
           are never removed from the archive subdirectory.

       PURGEBOUNCE=d
           Wait d days for the probe message, that automatically unsubscribes undeliverable
           addresses, to bounce (default: 14 days). Probe messages are sent three days (default)
           after the first message to an address bounces.

       PURGECMD=h
           Purge unconfirmed subscribe/unsubscribe requests after h hours (default: 48 hours).

       REMODERATE=h
           Resend a moderation reminder after h hours (default: 12 hours).

       REPORTADDR=address
           Mail daily reports of new and removed subscribers to this address. Must be set in
           order to receive reports. Provide an empty address to stop reporting.

       SIMPLECONFIRM=n
           If n is 1, confirmation requests may be acknowledged without adding “yes” to the
           subject line.

               Note
               The text in sub.tmpl, unsub.tmpl, and help.tmpl may need adjusting.

       SUBSCRIBE=option
           Set subscription options.  option is either "all", meaning that anyone can subscribe,
           or "mod", meaning moderated subscription requests, where all subscription requests are
           sent to the mailing list owner for approval. The default is "all".

       STARTPROBE=n
           Send a probe to a bouncing address n days after receiving the first bounce. Basically
           this means that an address must bounce for at least n days before it gets a probe
           message. The default is 3 days.

       Option names and settings are case sensitive.

           Note
           If you set up a digest list, you MUST set identical POSTARCHIVE option for both the
           main list and the digest list.

   DISPLAYING A SUBSCRIPTION RECORD
       The info command displays the subscription record for the requested address:

           couriermlm info directory user@domain

       This displays the subscription record for "user@domain", which typically consists of a
       copy of the initial subscription request, and confirmation.

   SENDING MESSAGES TO THE MAILING LIST
       The msg commands reads an E-mail message on standard input, and mails the contents of the
       message to the mailing list's subscribers.

       If the POST option is set to "subscribers", the message is rejected unless the address in
       its From: header is a subscriber to this mailing list.

       Control files headeradd and headerdel are read, and are applied to the message, as
       described previously.

   MAILING LIST COMMANDS
       Mailing list commands can be sent via E-mail to couriermlm by sending a message to
       <list-command@domain>. The "default" dot-courier(5)[1] file runs couriermlm to receive
       mail for all addresses of this form.

       couriermlm reads the DEFAULT environment variable, which is set by the Courier mail
       server, that indicates the specific command. The available commands are:

       help
           A simple autoresponder.  couriermlm mails the sender the contents of the help.tmpl
           file.

       subscribe
           A request to subscribe to this mailing list.  couriermlm reads the sender's address in
           order to determine what address to subscribe.

       subscribe-name=domain
           Explicitly specify the address to subscribe to the mailing list, instead of using a
           return address. In the previous example, sending a message addressed to
           <my-widgets-subscribe-john=domain.com@example.com> would result in a subscription
           request for <john=domain.com>. Any unusual punctuation characters in the address must
           be replaced by a plus sign, followed by two hexadecimal digits that represent the
           punctuation character's ASCII code.

       unsubscribe
           A request to unsubscribe to this mailing list.

       unsubscribe-name=domain
           Explicitly specify the address to unsubscribe from the mailing list.

       alias-subscribe
           Set up a write-only alias (see below).

       alias-subscribe-name=domain
           Explicitly specify the subscriber address for which a write-only alias needs to be set
           up.

       There are other commands that are used internally for maintaining the mailing list.

   WRITE-ONLY ALIASES
       Write-only E-mail aliases can send messages to the mailing list, but they do not receive
       any mailing list messages themselves. A write-only alias can be set up by any subscriber.
       Only one write-only alias is allowed per subscribed E-mail address. Write-only aliases are
       not needed for mailing list that has the POST=all option set.

       To set up a write-only alias, the subscriber sends a couriermlm alias-subscribe command.
       The subscriber's E-mail address can be explicitly specified in a similar manner as the
       subscribe command.

       The subject line of the E-mail message must contain the E-mail write-only alias to be set
       up, and nothing else.  couriermlm responds with a confirmation request, just like when
       subscribing to the list. This request must be acknowledged in the same way.

       A subscriber's write-only alias can be changed at any time by repeating this procedure.
       The new alias replaces the previous one. To prevent abuse, there's a limit of at most one
       alias-subscribe command every 30 minutes.

       Leave the subject of the E-mail message blank in order to remove an existing write-only
       alias,

   SETTING UP A MAILING LIST DIGEST
       couriermlm supports mailing list digests. Mailing list digests are created as a second,
       separate, mailing list. The create command initializes a second mailing list directory,
       and then additional configuration takes place which links the main mailing list to the
       digest list.

       If the mailing list address is list-address@example.com, the address of the digest version
       of the mailing list is usually list-address-digest@example.com, but it doesn't have to be
       this address. The only requirement is that the directory for the digest version of the
       mailing list must reside on the same file system as the directory for the mailing list
       itself, and both must be owned by the same userid.

       To set up a mailing list digest, first proceed with the steps to create the mailing list
       itself. After the mailing list is created and configured, proceed as follows:

       Create the digest list directory
           Execute the create command to create the digest version of the list:

               /usr/bin/couriermlm create \
                  /path/to/digest/list/directory \
                  ADDRESS=list-address-digest@example.com

           Use the full pathname to the mailing list directory, and the address of the digest
           version of the mailing list.

       Configure the digest list
           Execute the set command to set any appropriate options for the digest list. There one
           important differences to note: messages are not posted to the digest list directly, so
           there is no moderation option, however the digest version of the list can have
           moderated subscription requests.

       Link the two lists
           Set the DIGEST option for the main mailing list, specifying the directory of the
           digest list. This keyword lets couriermlm know that a digest version is available.

               Note
               You MUST set identical POSTARCHIVE option for both the main list, and the digest
               list.

       Create dot-courier(5)[1] files
           It is necessary to create dot-courier(5)[1] files for the digest list just like the
           main list, except for some important differences, which are noted below.

       Create cron(8) jobs
           It is also necessary to create cron jobs for the digest list exactly like the main
           list, to run the hourly and daily cleanup. It's possible to set up one set of cron
           jobs to run hourly and daily cleanups consecutively for both lists.

       Create a digest cron(8) job
           The digest creates and distributes the digest version of the list. It can be executed
           by a cron(8) job, or the command can be executed manually.

       The main mailing list is supported by three dot-courier(5)[1] files, as previously
       described: the posting address, the owner forwarding address, and the default address that
       handles administrative control messages. In the following example, the names
       $HOME/.courier-list, $HOME/.courier-list-owner, and $HOME/.courier-list-default are used
       to represent each one of these files, and the following names are used to represent the
       dot-courier(5)[1] files that correspond to the digest version of the mailing list:
       $HOME/.courier-list-digest, $HOME/.courier-list-digest-owner, and
       $HOME/.courier-list-digest-default. Note, however, that the digest version of the mailing
       list can have any name, not necessary the name of the list, followed by "digest".

       The contents of both $HOME/.courier-list $HOME/.courier-list-digest must be the same.
       Sending a message to the digest address should really end up sending a message to the main
       mailing list. Do not put the address of the digest mailing list directory in
       $HOME/.courier-list-digest, instead specify the address of the main mailing list
       directory. Just copy $HOME/.courier-list to $HOME/.courier-list-digest.

       However, the contents of $HOME/.courier-list-digest-default must specify the directory of
       the digest version of the mailing list. The digest list is managed separately from the
       main list, it has its own subscriber list that is separate from the list of subscribers to
       the main list.  $HOME/.courier-list-default can simply be copied to
       $HOME/.courier-list-digest-default, then the directory can be changed in the latter.

       $HOME/.courier-list-owner may use the same mailing list owner address as
       $HOME/.courier-list-digest-owner, or it can specify a different address. The both the
       digest and the main mailing list can have the same mailing list owner/moderator, or have a
       different owner/moderator.

       The following command must be executed in order to link the two lists together:

           /usr/bin/couriermlm set \
               /path/to/main/list/directory \
               DIGEST=/path/to/digest/list/directory

       Setting the DIGEST option on the main list lets couriermlm know that a digest version is
       available. The DIGEST option must either use an absolute pathname, or a pathname that's
       relative to the main list directory (NOT the current directory).

       When the DIGEST option is set, messages are simultaneously distributed to the mailing
       list's subscribers, saved in the archive subdirectory of the main list, then placed in the
       modqueue subdirectory of the digest list. Digest list do not employ moderation -- any
       moderation must take place on the main list -- so the modqueue subdirectory is recycled to
       compile individual messages for the digest.

       Finally, something needs to be done in order to actually distribute the digest to the
       digest list's subscribers. This is done by running the following command:

           /usr/bin/couriermlm digest /path/to/digest/directory N H

       This command creates a digest, and sends it out. The N and H arguments are optional. The
       digest is created only if there's at least N messages that are waiting to be sent in the
       digest list, or if the oldest message is at least H hours old. Both options default to 0,
       so the default behavior is to send a digest with all unsent messages.

       Note that when the digest is created, ALL unsent messages are packaged into the digest,
       even if some messages are more recent than the time interval specified by the H option. A
       cron(8) job can be set up to run the digest command, or run it manually.

       couriermlm automatically provides the From:, To: headers on a message digest. Additional
       headers may be specified by the headeradd file in the digest list directory. The headerdel
       file has no effect. Note that the individual messages in the digest are copies of the
       messages from the main mailing list, and thus have the headeradd and headerdel headers
       processed from the main mailing list directory.

BUGS

       couriermlm will not work if the Courier mail server's support for dot-courier(5)[1]
       extensions is disabled.

SEE ALSO

       courier(8)[7], dot-courier(5)[1], webmlmd(1)[3].

AUTHOR

       Sam Varshavchik
           Author

NOTES

        1. dot-courier(5)
           http://www.courier-mta.org/dot-courier.html

        2. Setting up a mailing list digest
           http://www.courier-mta.org/#digest

        3. webmlmd(1)
           http://www.courier-mta.org/webmlmd.html

        4. Mailing list commands
           http://www.courier-mta.org/#command

        5. localmailfilter(7)
           http://www.courier-mta.org/localmailfilter.html

        6. Write-Only Aliases
           http://www.courier-mta.org/#wonly

        7. courier(8)
           http://www.courier-mta.org/courier.html