[Mimedefang] filter by final recipient

Kevin A. McGrail kmcgrail at pccc.com
Wed Sep 21 12:25:04 EDT 2005

As you have identified, your ideas don't work because the problem is just a
fatal flaw in AOL's system of users improperly using the "this is spam" as a
filtering system.  They often use it rather than unsubscribing from
legitimate mailing lists.

#1 doesn't work because people mark "legit" mail because they are lazy.
#2 doesn't work because people are idiots and our efforts to educate them
have failed on this idea.
#3 is a bit harsh and likely to cause problems as more and more ISPs start
to implement similar systems

DO NOT RECOMMEND YOU DO WHAT you suggested doing in what I have marked as
option #4.  It just sounds like a privacy nightmare.

I suggest you apply for whitelist status and ignore the SCOMP TOS on a day
to day basis.  I look for patterns and issues out of whack but there is no
way to make it nil and I think AOL understands this which is why their rules
are to the best of my knowledge, percentage based.

> 1. Filter mail to AOL more heavily, as in rejecting more legit mail.
> This is not only hard to accomplish but will probably result in more
> helpdesk calls about mail not being delivered.
> 2. Find all the forwards to AOL once a month or so and send them all
> mail asking them not to hit "report as spam" for forwarded mail.  My
> guess is that plenty of them will start hitting "report as spam" when
> they get the reminders, and we'll be worse off than when we started.
> 3. Forbid people to forward to AOL.  This is pretty much what AOL is
> telling us by their actions.  This will create more helpdesk calls,
> and start chipping away at the alumni forwarding program.
[#4 KAM] > I don't like any of these, so I haven't given a whole lot of time
> figuring out option No. 1.  I guess a variant of No. 1 is to bounce
> back everything telling the sender what the AOL address is.

> I think filtering by final recipient can't be done in a practical way.
> There, if someone takes that as a challenge, good.  By final I mean
> by recipient after aliases and .forward files have been applied.

sendmail -bv might be what you want.  In your milter, run sendmail -bv and
the destination as well as cache the information.
for example, I added a forward in my kam dir to
kevin.mcgrail at somewhereelse.com (munged to protect the innocent)

sendmail -bv kam
kevin.mcgrail at somewhereelse.com... deliverable: mailer esmtp, host
somewherelese.com., user kevin.mcgrail at somewhereelse.com

Same with aliases & virtusertables:

sendmail -bv webmaster at stleos.com
adams... deliverable: mailer local, user adams
kmcgrail... deliverable: mailer local, user kmcgrail
adamsb... deliverable: mailer local, user adamsb


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