Someone has written a very handy utility for Exchange Server 2007 so that it can generate MailScanner-compatible “watermarks”. This means that you don’t need to send all your outgoing mail through a MailScanner server just to get the watermark added. The watermarks are added so that when you get a bounce notification (a DSN), MailScanner knows that it generated the original mail, and will therefore let the bounce error message through. By default, MailScanner will delete bounce notifications that it didn’t generate, as these are spam on the whole.

It is all documented here:
http://ifyoudo.net/post/2008/08/07/MailScannerWatermark-Plugin-For-Microsoft-Exchange-2007.aspx

Tags: Linux, MailScanner, Exchange, Watermarks