[Mailman-Users] Using mailman to take care of mailer-demons

J C Lawrence claw at kanga.nu
Tue Jan 15 23:58:54 CET 2002

On Tue, 15 Jan 2002 15:18:36 -0500 
Jon Carnes <jonc at haht.com> wrote:

> Some email systems send "bounces" from some weird addresses (as
> apposed to Mailer-Daemon, or some such address).  

A bounce is sole identified by having a null return address in the
envelope, and by nothing else.  None of the headers on a message are
significant in determining if a given message is a bounce, Not From:
not To:, none of them.

> As such, Mailman may not be able to interpret that the email is a
> bounce.  

The problem is that Mailman attempts the parse the body of a bounce
to determine subscriber address.  As the message body format is not
standardised this is an error prone process (which also explains the
attraction of VERP).

> Mailman may simply interpret the mail as a reply.  

Not if it has a null return-to envelope.  Guaranteed.

> There is a whole section in Mailman that is devoted to identifying
> different types of bounces.  The current list includes bounces
> from: Compuserve, Exim, Groupwise, Microsoft, Netscape, Postfix,
> SMTP, Smail, Yahoo, etc...

Right.  That's the message body parsing stuff, not the bounce
determination code.

> But folks use a wild number of differing Mailservers (like Lotus
> Notes, Connect2, etc...).  If they don't use a standard "bounce"
> format, and the bounce format they use has not been added to
> ~mailman/Mailman/Bouncers/..  then the message that comes back is
> seen as a reply from a user that is not on the list.

Nope, not unless the MTA in question grossly violates the RFCs and
uses a non-null return address.

J C Lawrence                
---------(*)                Satan, oscillate my metallic sonatas. 
claw at kanga.nu               He lived as a devil, eh?		  
http://www.kanga.nu/~claw/  Evil is a name of a foeman, as I live.

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