Provided by: mmh_0.4-1_amd64 bug


       slocal - asynchronously filter and deliver new mail


       slocal [address info sender] [-addr address] [-info data] [-sender sender] [-user
            username] [-mailbox mbox] [-file file] [-maildelivery deliveryfile] [-verbose |
            -noverbose] [-debug] [-Version] [-help]


       Slocal is a program designed to allow you to have your inbound mail processed according to
       a complex set of selection criteria.  You do not normally invoke slocal  yourself,  rather
       slocal  is  invoked  on  your  behalf  by  your  system's  Message Transfer Agent (such as
       sendmail) when the message arrives.

       The message selection criteria used by slocal is specified in the file `.maildelivery'  in
       the  user's home directory.  You can specify an alternate file with the -maildelivery file
       option.  The syntax of this file is specified below.

       The message delivery address and message sender are determined from the  Message  Transfer
       Agent  envelope  information,  if possible.  Under sendmail, the sender will obtained from
       the mbox `From ' line, if present.  The user may override these values with  command  line
       arguments, or arguments to the -addr and -sender switches.

       The  message  is normally read from the standard input.  The -file switch sets the name of
       the file from which the message should be read, instead of reading stdin.  This is  useful
       when debugging a `.maildelivery' file.

       The  -user  switch  tells slocal the name of the user for whom it is delivering mail.  The
       -mailbox switch tells slocal the name of the user's maildrop file.

       The -info switch may be used to pass an arbitrary argument to sub-processes  which  slocal
       may invoke on your behalf.

       The  -verbose  switch causes slocal to give information on stdout about its progress.  The
       -debug switch produces more verbose debugging output on stderr.  These  flags  are  useful
       when  creating  and  debugging  your  `.maildelivery'  file,  as they allow you to see the
       decisions and actions that slocal is taking, as well as check for syntax  errors  in  your
       `.maildelivery' file.

   Message Transfer Agents
       Most  modern  MTAs  including  sendmail,  postfix  and  exim  support  a .forward file for
       directing incoming mail.  You should include the line

            `| /usr/bin/mh/slocal -user username'

       in your .forward file in your home directory.  This will cause your MTA to  invoke  slocal
       on your behalf when a message arrives.

   The Maildelivery File
       The  `.maildelivery'  file  controls  how slocal filters and delivers incoming mail.  Each
       line of this file consists of five fields,  separated  by  white-space  or  comma.   Since
       double-quotes  are  honored,  these  characters  may  be  included in a single argument by
       enclosing the entire argument  in  double-quotes.   A  double-quote  can  be  included  by
       preceding it with a backslash.  Lines beginning with `#' and blank lines are ignored.

       The format of each line in the `.maildelivery' file is:

            header    pattern   action    result    string

            The  name  of  a header field (such as To, Cc,  or From) that is to be searched for a
            pattern.  This is any field in the headers of the message that might be present.

            The following special fields are also defined:

            source    the out-of-band sender information

            addr      the address that was used to cause delivery to the recipient

            default   this matches only if the message hasn't been delivered yet

            *         this always matches

            The sequence of characters to match in the specified header field.  Matching is case-
            insensitive, but does not use regular expressions.

            The  action  to  take  to  deliver  the  message.   When  a  message  is delivered, a
            `Delivery-Date: date' header is added which indicates the date and time that  message
            was delivered.

                This action always succeeds.

            file, mbox, or >
                Append  the  message to the mbox file named by string.  This is handled by piping
                the message to the mmh program rcvpack.  If  rcvpack  returned  successful,  then
                this action succeeds.

            pipe or |
                Pipe  the message as the standard input to the command named by string, using the
                Bourne shell sh to interpret the string.  Prior  to  giving  the  string  to  the
                shell, it is expanded with the following built-in variables:

                $(sender)     the out-of-band sender information

                $(address)    the address that was used to cause delivery to the recipient

                $(size)       the size of the message in bytes

                $(reply-to)   either the `Reply-To:' or `From:' field of the message

                $(info)       the out-of-band information specified

            qpipe or ^
                Similar  to  pipe,  but  executes  the  command directly, after built-in variable
                expansion, without assistance from the shell.  This action can be used  to  avoid
                quoting special characters which your shell might interpret.

            folder or +
                Store  the  message  in the mh folder named by string.  This is handled by piping
                the message to the mmh program rcvstore.  If rcvstore returned  successful,  then
                this action succeeds.

            Indicates how the action should be performed:

            A   Perform  the  action.   If  the  action  succeeds, then the message is considered

            R   Perform the action. Regardless of the outcome of the action, the message  is  not
                considered delivered.

            ?   Perform  the  action  only  if the message has not been delivered.  If the action
                succeeds, then the message is considered delivered.

            N   Perform the action only if the message has not been delivered  and  the  previous
                action  succeeded.   If  this  action  succeeds,  then  the message is considered

            The delivery file is always read completely, so that several matches can be made  and
            several actions can be taken.

   Security of Delivery Files
       In  order  to  prevent security problems, the `.maildelivery' file must be owned either by
       the user or by root, and must be writable only by the owner.  If this is not the case, the
       file is not read.

       If  the `.maildelivery' file cannot be found, or does not perform an action which delivers
       the message, then slocal will check for a global delivery file  at  /etc/mmh/maildelivery.
       This  file  is  read according to the same rules.  This file must be owned by the root and
       must be writable only by the root.

       If a global delivery file cannot be found or does not perform an action which delivers the
       message, then standard delivery to the user's maildrop is performed.

   Example Delivery File
       To summarize, here's an example delivery file:

       # .maildelivery file for mmh's slocal
       # Blank lines and lines beginning with a '#' are ignored

       # File mail with foobar in the `To:' line into file foobar.log
       To        foobar    file    A       foobar.log

       # Pipe messages from coleman to the program message-archive
       From      coleman   pipe    A       /bin/message-archive

       # Anything to the `nmh-workers' mailing list is put in
       # its own folder, if not filed already
       To        nmh-workers  folder ?     nmh-workers

       # Anything with Unix in the subject is put into
       # the file unix-mail
       Subject   unix      file    A       unix-mail

       # I don't want to read mail from Steve, so destroy it
       From      steve     destroy A       -

       # Put anything not matched yet into mailbox
       default   -        file    ?       mailbox

   Sub-process environment
       When  a  process is invoked, its environment is: the user/group-ids are set to recipient's
       ids; the working directory is the recipient's home  directory;  the  umask  is  0077;  the
       process has no /dev/tty; the standard input is set to the message; the standard output and
       diagnostic output are set  to  /dev/null;  all  other  file-descriptors  are  closed;  the
       environment  variables $USER, $HOME, $SHELL are set appropriately, $PATH is preserved, but
       no other environment variables exist.

       The process is given a certain amount of time to execute.  If the process  does  not  exit
       within  this  limit, the process will be terminated with extreme prejudice.  The amount of
       time is calculated as ((size / 60) + 300) seconds, where size is the number  of  bytes  in
       the message (with 30 minutes the maximum time allowed).

       The  exit status of the process is consulted in determining the success of the action.  An
       exit status of zero means that the action succeeded.  Any other exit status  (or  abnormal
       termination) means that the action failed.

       In  order  to  avoid  any  time  limitations,  you might implement a process that began by
       fork()-ing.  The parent would return the appropriate  value  immediately,  and  the  child
       could  continue  on,  doing whatever it wanted for as long as it wanted.  This approach is
       somewhat risky if the parent is going to return an exit status of zero.  If the parent  is
       going  to  return  a non-zero exit status, then this approach can lead to quicker delivery
       into your maildrop.


       $HOME/.maildelivery        The file controlling local delivery
       /etc/mmh/maildelivery      Rather than the standard file
       /var/mail/$USER            The default maildrop


       rcvdist(1), rcvpack(1), rcvstore(1), mh-format(5)


       `-maildelivery' defaults to $HOME/.maildelivery
       `-mailbox' deaults to /var/mail/$USER
       `-file' defaults to stdin
       `-user' defaults to the current user


       slocal does neither read nor change the context.  Nor does it read the user profile.


       Slocal was originally designed to be backward-compatible with  the  maildelivery  facility
       provided  by  MMDF-II.   Thus,  the  `.maildelivery' file syntax is somewhat limited.  But
       slocal has been modified and extended, so that is it no longer compatible with MMDF-II.

       In addition to an exit status of zero, the MMDF values RP_MOK (32) and RP_OK (9) mean that
       the  message has been fully delivered.  Any other non-zero exit status, including abnormal
       termination, is interpreted as the MMDF value RP_MECH (200), which means `use an alternate
       route' (deliver the message to the maildrop).

       The `suppress duplicates' function had been removed from slocal for simplicity reasons.


       Only two return codes are meaningful, others should be.

       Slocal   was   originally  designed  to  be  backwards-compatible  with  the  maildelivery
       functionality provided by MMDF-II.