[Mailman-Users] relaying spam using mailing lists

Heather Madrone heather at madrone.com
Wed Mar 15 20:35:33 CET 2006

At 8:32 PM +0200 3/15/06, Gadi Evron wrote:
>A friend of mine just wrote about what happened to an ezmlm mailing list
>he runs, and how it was recently used to relay spam (quoted below).
>All mailing list managers return bounces of some sort, for
>subscriptions, unsubscriptions, moderation, etc. (*configuration
>dependent*), some just quote the subject line though, as an example.

My installation of Mailman doesn't.  I have spam filters that make
sure that poorly-formed requests don't get to Mailman.

>Do we risk blocking by black lists for allowing mailing list bounces?

At this point in time, it's fairly net-unfriendly to run a mail reflector
that isn't protected by spam filters.  If anyone uses your mail reflector
to propagate spam, you'll have a hard time getting your domain

>We all see spam bouncing off our lists, how do we distinguish what's
>what? Especially if these are bounces themselves?
>How would mailman be vulnerable, if at all?

Don't relay mail to Mailman that you don't want Mailman to receive.
Install good spam filters and tune your MDA so that it won't deliver
scattershot messages to Mailman.

Thank you,

Heather Madrone <heather at madrone.com>

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