[ On , January 23, 2004 at 08:06:45 (+0200), Andrew Lewis wrote: ]
> Subject: [Exim] Stopping out-of-office auto-reply mail loops
>
> Currently I am experiencing problems where-in one user will set their
> out-of-office auto-reply on, and then mail another user who's auto-reply
> is on, causing an infinite mail-loop.
Perhaps you can at least point out the problem and its solutions to the
author/vendor of the software your users are misusing.
Here are some basic rules for automated e-mail agents such as vacation
autoresponders:
No response should _ever_ be sent to the list posting address.
No response should ever be sent unless the recipient's mailbox is part
of either the ``To:'' or ``Cc:'' headers of the mail. This will almost
always prevent your e-mail autoresponder from replying directly to a
mailing list injection/posting address even if non of the other
remaining mechanisms prevent a reply.
No response should be sent to messages from ``-OUTGOING'', ``-RELAY'',
``LISTSERV'', ``-REQUEST'', ``MAILER'', or ``MAILER-DAEMON'' (where
these strings are case insensitive suffixes of the base mailbox name for
the sender or originator address, and should match any and all domains).
No response should ever be sent to the same address within some decent
length of time, such as seven full days. This will prevent mailer loops
from becoming denial of service attacks and will also help prevent
annoying human readers who don't need instantaneous reminders of your
status every few moments.
Finally, and most importantly, no reply should ever be sent if a
``Precedence:'' header is found that contains the value ``bulk'',
``list'', or ``junk''!
--
Greg A. Woods
+1 416 218-0098 VE3TCP RoboHack <woods@???>
Planix, Inc. <woods@???> Secrets of the Weird <woods@???>
