1 – 2003 Exchange Server Standard server
2- 2010 Exchange Server Standard servers, Backend (Mailbox) / Frontend (Client/Hub)
No Edge role
Receive Connector on Hub has anonymous connections enabled
When NAT is directed to 2010 Hub server, external e-mail does not reach the user’s mail box. Internally sent e-mail is delived fine. Tracking Log Explorer shows that the server received the e-mail, but didn’t deliver it (no receipient address listed). When NAT is directed back to the 2003 server, mail delivery works normally.
What could be causing the mail to be not delivered to the user’s mail box?