Yes that is what is happening. Your spam filter is what is doing the talking to the outside mail servers, so it needs to be aware of your recipient lists in AD. Most good ones that work with Exchange are. Take a look at its settings and options.
From: Bill Songstad (WCUL) [mailto:administra...@waleague.org] Sent: Wednesday, August 19, 2009 2:00 PM To: MS-Exchange Admin Issues Subject: RE: NDRs backscatter and such I wonder if these messages are being accepted by the spam filter (it sits in an SMTP sink on the exchange box) thus thwarting the filtering.
