[spambayes-dev] RE: Delivery Status Notification (Failure)

[Seth Goodman]

> From: spambayes-dev-bounces at python.org
> [mailto:spambayes-dev-bounces at python.org]On Behalf Of Tony Meyer
> Sent: Monday, September 20, 2004 8:54 PM

<...>

> > What do the headers look like?
>
> This (and VERP) was the clue I needed, though (thanks!).  The (relevant)
> headers of the attached (bounced) messages are (for one such message):

I didn't get an attachment either from the direct email from you or from the
list.  Try again?  Perhaps that gmx account was the culprit, but you can't
tell without the rest of it.  As an interesting aside, I don't seem to get
any such bounce messages when I post, unless I'm failing to notice them in
my spam folder.

The scenario sounds like when you post to the list, the list distributes the
mail and then some broken MTA bounces back to the original poster instead of
the list.  Since the return-paths all go to python.org, whether or not they
are VERP, you are dealing with a broken MTA.  I have heard of some
antiquated, broken MTA's that bounce to the 2822 From: address instead of
the 2821 MAIL FROM: address.  This is the most likely scenario for what you
describe, and deleting the user is definitely in order.  If you want to be
really nice, you could write a note to the postmaster for the bouncing
domain and let them know that their bounce practices are non-compliant with
RFC821 and 2821 and will abuse virtually every modern mailing list should an
account disappear that has active list subscriptions.  For a large list,
this is a lot of abuse.  Make sure to use the domain that sends the bounce,
not the domain of the subscribed address, since the latter may be completely
innocent in case of forwarding.  Unfortunately, five will get you ten that a
system this broken doesn't have a working postmaster address, but it's worth
a try.

I'm still curious why only a few of the list postings get distributed with a
VERP address and the rest don't.  Any idea on this?

If there is no VERP return-path, the list software can't automatically
unsubscribe dead accounts, which is a nice feature.

--

Seth Goodman