Mail ERROR: [20302] Interrupted

I have IPSentry installed on a dedicated Windows 2003 Server. It sits on the same sub-net as my Windows 2003 Small Business Server that runs my mail. ( Exchange )

When I configure the "Default" mail alert to point (via the internal IP address) of my mail server I keep receiving the following failed message;

4/7/2011@18:08>Starting test. . .
4/7/2011@18:08>Loading data for test. . .
4/7/2011@18:08>Loaded {default}. . .
4/7/2011@18:08>Testing. . .
4/7/2011@18:08>Testing Failure Alert on {default}
4/7/2011@18:08>Setup Email. . .
4/7/2011@18:08>Mail Alert To: brian.dilks@actualdomain.com via 172.XX.X.XX
4/7/2011@18:08>Mail ERROR: [20302] Interrupted.
4/7/2011@18:08>Finished: Interrupted.
4/7/2011@18:08>Failed.
4/7/2011@18:08>Total processing time: 31 milliseconds

I have reviewed the configure email alert in the manual; I mixed and matched various user names & format and get the same  " Test Alert failed! Interrupted"

Lastly, there is no firewall or software on either of the servers that prohibits port 25 traffic to the Exchange server. We take care of that using edge devices.

Thanks in advance for input

I am using version 5.50

RE: allowing SMTP from other servers; yes, the server is on the same sub-net, I have even have an "exception set " for the IP address in the Exchange "Message Delivery Properties."

RE: TLS/SSL - no, I do not have that set in the Exchange server

RE: Authentication; I tried Active Directory, Simple, and anonymous

RE: From address; yes I tried administrator, and I tried creating an IPSentry user with a mail box.

OK, I email the screen shot to the support@ipsentry.com

RE point to MX; the MX record is point to a pre-scanning service, all mail is scanned from an outside AV & Spam source prior to hitting our Exchange server. So, pointing to it does not work unless we have something to relay off of.