RE: [Exim] Stopping out-of-office auto-reply mail loops

Ah, thank you. I have been thinking quite a bit about this
vacation/auto-reply stuff for a while now and still can't seem to fully make
up my mind about where it should be sent to.

Some say the From: or Reply-To: headers (which can make sense), but then I
think about these possibly being faked, or if someone is spammed (not high
enough to be discarded/dropped) and has a vacation message on, using these
fields could result in a bunch of emails sent out to faked addresses.

Others say the envelope sender, which makes sense too - possilby more than
others. If emails were sent to this, (I believe it's $return_path I'm
referring to, not the $sender_address or whatever) it would avoid sending to
bouncebacks (empty address, so it's discarded) automatically, and if a list
send a message, although annoying, only one message would get sent to the
list, thus everyone would know and you wouldn't send duplicates (rather than
just a message to every individual user). It could also avoid the high
volume possibly created by spam (although I have no idea how spam software
works, so I don't know if it would use different envelope senders).

Currently I'm thinking of using the $return_path variable, mainly because
it's a lot easier, and somewhat safer than using $header_from: (or at least
making some kind of long winded ${if ...} test based on from: and reply-to:
headers like a MUA should pick from).

However (possibly a new thread for this), I now come up with a new dilema -
the built in "once" stuff can't interface with MySQL, thus I have to try and
hack one in using conditions, but then... I've already got the biggest
condition line ever for my router since I check for null senders, the
precedence: header setting, and a MySQL query to see if the user has a
vacation message set and active. All this has to be in just *one* condition
statement because you can't have multiple condition statements in a router
like you can ACLs (which sucks I think!). Also, there's no other useless
command I could use to stick in other MySQL tests and such, so there's
apparently no way I can emulate the once feature using MySQL :(

So for those that do have vacation/auto-reply setups for virtual domain user
type setups using mostly SQL back ends, what sort of router/transport
entries do you have for this type of situation?

Eli.

(BTW, sorry for my top posts - Outlook's only good message format is top
posting :()

-----Original Message-----
From: exim-users-admin@??? [mailto:exim-users-admin@exim.org] On Behalf
Of Greg A. Woods
Sent: Saturday, January 24, 2004 12:22 AM
To: eli-list@???
Cc: Exim User's Mailing List
Subject: RE: [Exim] Stopping out-of-office auto-reply mail loops

[ On Friday, January 23, 2004 at 16:03:50 (-0500), Eli wrote: ]
> Subject: RE: [Exim] Stopping out-of-office auto-reply mail loops
>
> Where are these all typically seen? I obviously know about mailer-daemon,
> but I've never seen the others in email addresses? Just wondering why
these
> shouldn't have autoreplies sent to them, since I'm just doing up an auto
> reply router/transport myself.
>
> >No response should be sent to messages from ``-OUTGOING'',

typical of several 0lder mailing lists, IIRC

> ``-RELAY'',

I can't remember where that one comes from. :-)

> >``LISTSERV'',

the mailbox used by several mailing list management software packages

I guess I should add "MAJORDOMO" (and maybe "MAILMAN"?) to this list! :-)

> ``-REQUEST'',

typically used for auto-responders for many mailing lists

> ``MAILER'', or ``MAILER-DAEMON''

typically what the empty envelope sender address ("<>") expands to for
presentation in in an RFC-822 header.

> What about postmaster? I thought about possibly blocking that, but then I
> thought that postmaster should be a real person, and sending a vacation
> message to them may help let them know if someone can't get to an issue
> right away.

exactly. :-)

The idea with avoiding the above is to avoid needless interactions with
the most common autoresponders.

(remember the 7-day delay between sending another reply is what actualy
prevents any mail loops from having any serious impact)

--
                        Greg A. Woods

+1 416 218-0098                  VE3TCP            RoboHack
<woods@???>
Planix, Inc. <woods@???>          Secrets of the Weird
<woods@???>

--

## List details at http://www.exim.org/mailman/listinfo/exim-users Exim
details at http://www.exim.org/ ##