Re: unexpected UNDELIVERED MAIL

From: Allen Brooker (allen@brooker.gb.net)
Date: 11/30/01 

Message-ID: <004701c179ce$8c108000$0201a8c0@switch>
From: "Allen Brooker" <allen@brooker.gb.net>
To: <focus-linux@securityfocus.com>
Subject: Re: unexpected UNDELIVERED MAIL
Date: Fri, 30 Nov 2001 18:32:57 -0000

You could look at denying relaying - ie. you have to check your email before
you can send email.
I'm presuming your control your own mail server - which is what it sounds
like.

Is the server returning the whole of the original email? You could try
looking at the headers to track down the culprit.

HTH
Allen