A customer of mine just got a new T1 connection, and everything works except for emailing comcast.net addresses. They have their own exchange 2003 box, running on SBS 2003. The error we get (after being delayed) is the following:
The following recipient(s) could not be reached:
firstname.lastname@example.org on 1/23/2008 9:36 AM
Could not deliver the message in the time limit specified. Please retry or contact your administrator.
I've already checked the delivery FQDN (which is tapestrymedical.com). i tried changing it to mail.tapestrymedical.com (which resolves to the public IP of the router), but that didn't help. we also put in a new router at the same time, but i'm not sure what else would need to be opened in order for this to work properly.