I have a completely fresh install of SBS 2008 running Exchange 2007. There are about 15 users who can all email internally and externally. One of those users can't email internally though. For example, if he is firstname.lastname@example.org, he can't email to email@example.com. He gets a non-delivery report:
"The recipient's e-mail address was not found in the recipient's e-mail system. Microsoft Exchange will not try to redeliver this message for you. Please check the e-mail address and try resending this message, or provide the following diagnostic text to your system administrator."
He is using Outlook2007.
This user can log right in to the Remote Web Worplace and send to anyone (internal addresses and external) perfectly fine. So imaybe the problem is related to his Outlook program.
Any ideas what could be wrong?