Intermittent Exchange 2007 NDR
Posted on 2012-09-18
One user is receiving errors like this from one or two senders each day. Attachments are usually involved but are small (usually under 5 MB)
System is SBS 2008, content filtering is off. SMSE 6.5 is not trapping the messages in quaratine.
The IP w.x.y.z in the error is the static IP of the SBS box.
I have checked and they are not blacklisted.
Any idea what could be causing this error ?
Sent: 13/09/2012 8:46 AM
The following recipient(s) cannot be reached:
xxxxxxx xxxxxxxxxxx on 13/09/2012 9:01 AM
The e-mail account does not exist at the organization this message was sent to. Check the e-mail address, or contact the recipient directly to find out the correct address.
<xxxxxxxxxxxxxxxxxxxx #5.1.1 smtp;550 5.1.1 Relay denied for xxxxxxxxxxxxxxxx via w.x.y.z>