Someone in our org (yaddayadda.com) mails another person at (woohoo.com). Here, an NDR is received:
firstname.lastname@example.org on 6/12/2006 9:56 AM
You do not have permission to send to this recipient. For assistance, contact your system administrator.
<dunsvr06.yaddayadda.com #5.7.1 smtp;550 5.7.1 Unable to relay for email@example.com>
Apparently, they have determined somehow that this problem is -not- on their side (woohoo.com). They have a hosted email service that I do not have any details on.
We have Exchange 2003 SP1 Native.
How can this be a problem on our side when we simply send the message to them? The users report that sometimes, the message goes through fine, other times, they get this NDR. This issue appears to be isolated to this particular domain (woohoo.com).
This *could* be related in some way to my other question... http://www.experts-exchange.com/Networking/Q_21901858.html