[Mailman-Users] Forged from headers and non existent lists

[Heather Madrone]

At 12:49 PM -0800 3/16/06, stupidmail4me wrote:
>My site is getting a lot of spam sent to my lists.
>They are being sent from unknown people using forged
>from headers. Mailman then sends an email to these
>forged from headers telling them so and so list
>doesn't exist. Most of these forged from headers
>aren't real addresses, so there begins loops of
>mailman trying to send out a message, and their email
>servers telling mine that address doesn't exist.
>
>Is there an option in Mailman to just disregard
>messages sent to lists that don't exist? I don't want
>to send a message informing them that the list doesn't
>exist, I just want Mailman to ignore it. Is this
>possible?

Others might disagree, but I don't think that MTA ought to
deliver messages to list (or list administration) addresses that
don't exist.  The MTA should refuse to accept delivery of
such messages.

I also think that judicious pre-Mailman use of spam filters
cuts way down on the amount of junk that Mailman has to
process.  I've been running one of my lists since 1996 (it
has existed since 1989), and the admin addresses for that
list gets hundreds of spam attempts every single day.  After
some tinkering, I've managed to adjust the filters so they
keep out almost all the spam while letting through almost all
the legitimate requests (I do check manually to make sure that
no valid requests get dumped by mistake).

Bouncing spam is, ironically enough, one of the best ways
to get branded a spammer by certain ISPs.  I think we have
a duty to at least try to weed out the spam and not have our
autoresponders make the problem worse by trying to bounce
the stuff.

-- 
Heather Madrone  (heather at madrone.com)  http://www.madrone.com

"Everything I never wanted to know I learned from the Internet."
    -- Morgayn Madrone, age 17