diplodocus.org Git - nmh/blob - docs/MAIL.FILTERING

   1 INTRODUCTION
   2 ------------
   3 It is a common practice when using nmh to filter your inbound mail
   4 directly into nmh folders.  There are several programs which allow you
   5 to do this, of which two common ones are procmail and slocal.
   6
   7 SLOCAL
   8 ------
   9 The slocal command is part of the nmh distribution.  It is a fairly
  10 simple mail filtering program.  Check the slocal man page for an example
  11 filtering file (called .maildelivery).
  12
  13 PROCMAIL
  14 --------
  15 Probably the most popular mail filtering command is procmail.  It can
  16 filter mail into standard mbox-style spool files, as well as into MH/nmh
  17 style folders.
  18
  19 Although procmail knows how to put a message directly into an nmh folder,
  20 this is not recommended.  Procmail doesn't know about nmh sequences.
  21 Instead you should have procmail use the nmh command `rcvstore' to put
  22 the message into the folder.  The `rcvstore' command will (by default)
  23 add each new message to the "unseen" sequence, so you can detect new
  24 messages in folders with the `flist' command.
  25
  26 Also, nmh commands generally like to keep mail messages in RFC-822
  27 format.  But by default, procmail will leave the first line of the
  28 message unchanged.  This line (which usually begins with "From ") is
  29 not in the standard RFC-822 format.  It is recommended that you use the
  30 command `formail' (which comes in the procmail distribution) to rewrite
  31 this line so that it begins with the header name "X-Envelope-From:".
  32 An example of how to do this is given below.
  33
  34 The reason the header name "X-Envelope-From:" is recommended, is that the
  35 nmh command `packf' (as of version 0.23) will check for this header when
  36 packing folders.  The `packf' command knows how to undo the rewriting
  37 of the "From " line to the "X-Envelope-From:" line.  By checking for
  38 this header name, `packf' is able to pack the folder into exactly the
  39 form that is used if procmail delivers to the standard mail spool.
  40
  41 If you do not rewrite the "From " line into this format, the `packf'
  42 command will still work.  But it may create fake "From " lines which
  43 are not the same as the originals.
  44
  45 Alternatively, you might be able to suppress generation of the "From "
  46 line.  If your procmail invocation includes the -f or -r option,
  47 remove.  Those options add a "From " line to incoming beginning of
  48 messages that do not have them.
  49
  50 Here is a typical .procmailrc file for using procmail in conjunction
  51 with nmh.  For more information, see the manual pages for procmail,
  52 procmailrc and procmailex.
  53
  54 ###################################################################
  55 # .procmailrc
  56 ###################################################################
  57 # To use procmail, put the next line in your .forward file:
  58 # "|IFS=' ' && exec /usr/local/bin/procmail -f- || exit 75 #XXX"
  59 # Do not remove the double quotes.  Change XXX to your username.
  60 # Edit path to procmail above, and the VARIABLES below, as needed.
  61 # Adapt the MAILING LIST section below for lists you subscribe to.
  62 # Your .forward needs to be world-readable, but not world-writable.
  63 ###################################################################
  64 # This .procmailrc is written for use with nmh/mh/exmh/mh-e
  65 ###################################################################
  66
  67 ### VARIABLES ###
  68 VERBOSE=off
  69 SHELL=/bin/sh
  70 PATH=/usr/local/nmh/lib:/usr/local/nmh/bin:/usr/bin:/usr/local/bin
  71 MAILDIR=$HOME/Mail
  72 LOGFILE=$MAILDIR/procmail.log
  73 LOCKEXT=.lock
  74
  75 #################
  76 # CLEANUP MESSAGE
  77 #################
  78
  79 # Force the "From user date" to become part of header
  80 :0 Whf
  81 | formail -z -R 'From ' X-Envelope-From:
  82
  83 ###############
  84 # MAILING LISTS
  85 ###############
  86
  87 :0 w: nmh-workers/$LOCKEXT
  88 * ^Resent-from: *nmh-workers
  89 | rcvstore +nmh-workers
  90
  91 # catches exmh-{announce,users,workers}
  92 :0 w: exmh/$LOCKEXT
  93 * ^TOexmh
  94 | rcvstore +exmh
  95
  96 # Catch junk.  Don't add it to "unseen" sequence (nmh only)
  97 :0 w: junk/$LOCKEXT
  98 * ^(reply-to|from|sender):.*(spammer|flamer|evil-host)
  99 | rcvstore -nounseen +junk
 100
 101 ################
 102 # DEFAULT ACTION
 103 ################
 104 :0 w: inbox/$LOCKEXT
 105 | rcvstore +inbox
 106