# Sample Courier Maildrop file to demonstrate filtering messages
# according to:
#
#   1 - Mailing list headers.  
#
#   2 - How Spamassassin scores them.
#
#   3 - Whether Anomy Sanitizer finds an executable attachment
#       and drops it.
#
# Real mailing list sorting may be trickier if there isn't a 
# clearly identifiable list-related header line.

logfile "mailfilter-log.txt"

log "========"

if ( /^Subject: Test1/ )
{
    log "-------------------------------------------- Test1 found "
    to "Maildir/.blah"
}


if ( /^List-Id: IETF Discussion/ )
{
    log "-------------------------------------------- IETF "
    cc "Maildir/.Lists.IETF"
    xfilter "subjadd [IETF]"
    DELTAG=$DTAG
    to "$LMB"
}

                                 # Copy all messages which are not
                                 # caught by one of the above mailing
                                 # list filters to be copied to 
                                 # special folder so I can find a
                                 # message, if I want to, in 
                                 # the state before Spamassassin
                                 # looked at it (and therefore wrote
                                 # something in the headers) and before
                                 # Anomy Sanitizer may have defanged
                                 # its HTML or dropped its attachment.
                                 #
                                 # In this example, "Pre-Filter-Inbox"
                                 # is a mailbox within the mailbox:
                                 # "0-Inbox-Old" - as is another
                                 # mailbox used at the end:
                                 # "Post-Filter-Inbox".
                                    
cc "Maildir/.0-Inbox-Old.Pre-Filter-Inbox"                

xfilter "/usr/bin/spamassassin -x"
 
                               # Look out for marginal scoring spam & 
                               # put it somewhere I can scrutinise it 
                               # easily, away from the worst stuff.
                               # If the threshold of 3.0 is too low
                               # there will be many false-postives in
                               # -SPAM-marginal, and I will need to
                               # fish them out manually.
                    
if (   ( /X-Spam-Status: No, score=3./  )    \ 
     ||( /X-Spam-Status: No, score=4./  )    \ 
     ||( /X-Spam-Status: Yes, score=5./ )    \ 
   )       
{
    log "-------------------------------- Spam marginal. "    
    to "Maildir/.-SPAM-marginal"         
}

                                # Watch out for header line added by
                                # Spamassassin, which it will be for
                                # anything scoring 5.0 or above.
                                #
                                # Don't allow any blank lines after 
                                # the if statement!
if (  /^X-Spam-Flag: YES/  )
{
  log "----------------------------------- Spam general. "
  to "Maildir/.-SPAM"           
}
                                # If we are still processing the
                                # the message, it is because its
                                # Spamassassin score was below 3.0.

                                # Some debugging lines and a place to 
                                # save things when I am tweaking 
                                # Anomy Sanitizer: a mailbox "Debug".
cc "Maildir/.Debug"
log "Send to Anomy"

                                # Set up the environment variable ANOMY 
                                # to keep Anomy happy.
ANOMY=/usr/local/anomy/ 

                                # Set up two other environment 
                                # variables, as required by UNICODE.TXT.
LC_ALL=C
LANG=en_US 

                                # Filter the message via stdin to Anomy, 
                                # with the config file specified, 
                                # logging output being appended to the
                                # Maildrop log file and then the output 
                                # being piped to cat so cat's stdout 
                                # sends it back to Maildrop.  The use
                                # of "2>>" for appending stderr with 
                                # the log material means we need the 
                                # "| cat".
                                #
                                # If Anomy's conf file has:
                                #
                                #   feat_log_inline = 0
                                #   feat_log_stderr = 1
                                #
                                # Then a report of Anomy's progress in 
                                # working on the message will be 
                                # appended to the Maildrop log file.  
                                # This seems to work fine, so 
                                # presumably each "log" line for 
                                # Maildrop means it opens and closes 
                                # the log file.  There could be 
                                # multiple instances of Anomy 
                                # running at the same time, each on
                                # different message.  
                                #
                                # Anomy Sanitizer can be extremely
                                # verbose in its log output.

xfilter "/usr/local/anomy/bin/sanitizer.pl /usr/local/anomy/anomy.conf 2>>~/mailfilter-log.txt | cat"

log "Anomy done."

                                # Watch out for text added to body 
                                # by Anomy Sanitizer when it *drops* a 
                                # file which is an attachment within
                                # the email - not just when it renames 
                                # a file or defangs some HTML in the 
                                # message.  This:
                                #
                                # *** Attached file dropped ***
                                #
                                # is  a part of the drop message I specified
                                # in the Anomy Sanitizer config file.
                                # It always starts at the start of a
                                # line.
                                #
                                # The backslash escapes the asterisk.
                                # An ordinary asterisk is a special
                                # character in the PCRE pattern matching
                                # language, so use:
                                #
                                #   \*
                                #
                                # to match an asterisk.
                                #
                                # ":b" means look in the body, rather 
                                # then the headers.


if (  /^\*\*\* Attached file dropped \*\*\*/:b ) 
{
    log "--------------------------------- Executable attachment! " 
    
                                # Make this "cc" for copy or "to" to 
                                # not send it to Inbox.
                                # Copy it to the "-Executable" 
                                # mailbox.
    cc "Maildir/.-Executable"             
    
                                # Add something highly visible to the 
                                # subject line and deliver the message
                                # to the Inbox.  The dropped attachment
                                # is replaced by a text file attachment
                                # with the warning text.
                                #
                                # Intrepid users who want to find a
                                # copy of the message with its original
                                # attachment will find it in the
                                # mailbox "Pre-Filter-Inbox", as
                                # described above.
                                       
    xfilter "subjadd ~~~[Executable]"
    to "Maildir"
}

                                # Copy all messages which are not
                                # caught by one of the above filters
                                # to be copied to special folder
                                # so I can find them, even if I 
                                # accidentally delete it from the
                                # Inbox.  I don't intend to keep 
                                # this mailbox's contents for long.
                                    
cc "Maildir/.0-Inbox-Old.Post-Filter-Inbox"


                                
    log "- - - - - - - - - - - - - - - - - - - - - -  No match"
   
                                # Deliver to the Inbox.
    to "Maildir"