[Mimedefang] auto reply / vacation

[Kevin A. McGrail]

> But I don't need that.  If you are going to write your own, I'd encourage
> you to study the vacation(1) source code; it contains measures that
> eliminate most of the worst auto-responder behaviour.

Actually, I found the vacation program to be woefully problematic in 
replying to spam, lists, etc. and had worked for some months on it and 
submitted a patch.  The Sendmail authors rejected the patch because they 
considered too specific.  I disagreed and stopped using vacation because I 
found that procmail was a better solution though a front-end to edit it for 
end users would be a good idea.

Here were some specs I wrote at the time:

#1 not reply based on subject contents, for example "do not reply to subject 
beginning with *** SPAM *** / [SPAM] / [ADV]  or containing [SEXUALLY 
EXPLICIT], etc."
#2 Do not reply to message of "precedence of bulk"
#3 Do not reply to mailing lists.
#4 Do not reply to NDR and DSN messages.
#5 Do not reply to more than one time per day.
#6 Do not reply to Vacation and other out of office messages.
#7 Do not reply to Daemons

So for example, here's an untested procmail script (based on the procmailrc 
example)

#1 could be solved with the X-Spam-Status and my focus on SA to catch spam.
#2 could be solved with FROM DAEMON (from man procmailrc)
      If the regular expression contains `^FROM_DAEMON' it will be 
substituted by `(^(Mailing-List:|Precedence:.*(junk|bulk|list)|To: Multiple 
recipients of
       |(((Resent-)?(From|Sender)|X-Envelope-From):|>?From )([^>]*[^(.%@a-z0-9])?(Post(ma?(st(e?r)?|n)|office)|(send)?Mail(er)?|daemon|m(mdf|ajordomo)|n?uucp
       |LIST(SERV|proc)|NETSERV|o(wner|ps)|r(e(quest|sponse)|oot)|b(ounce|bs\.smtp)|echo|mirror|s(erv(ices?|er)|mtp(error)?|ystem)|A(dmin(istrator)?|MMGR
       |utoanswer))(([^).!:a-z0-9][-_a-z0-9]*)?[%@>\t ][^<)]*(\(.*\).*)?)?$([^>]|$)))', 
which should catch mails coming from most daemons (how's that for a
       regular expression :-).
#3 could be solved with FROM_DAEMON and the List-Id check
#4 could be solved with using VBOUNCE with SA
#5 is harder but you can use a 16K cache file. It won't respond a second 
time until the cache file fills up.
#6 could be solved with usign VBOUNCE with SA
#7 FROM DAEMON again



SHELL=/bin/sh

:0 Whc: vacation.lock
* !^X-Spam-Status: Yes
# Don't reply to daemons and mailinglists
* !^FROM_DAEMON
# Don't reply to mailinglists
* !^List-Id:
# Don't reply to Bounces
^X-Spam-Status:.*BOUNCE_MESSAGE
# Mail loops are evil
* !^X-Loop: kmcgrail at pccc.com
| formail -rD 16384 vacation.cache

:0 ehc         # if the name was not in the cache
| (formail -rI"Precedence: junk" -A"X-Loop: kmcgrail at pccc.com" ; \
echo "I don't care about you and this email proves it." ; \
echo "" ; \
echo "Regards," ; \
echo "KAM" ; \
) | $SENDMAIL -oi -t -f kmcgrail at pccc.com


Regards,
KAM