We moved mailboxes from one forest to another. Both servers are Exchange 2010.
One mailbox (and ONLY one mailbox) can't receive external mail.
All firewall, SMTP, Public DNS, routing, etc. is working. All other mailboxes are working fine.
I exported the mailbox to a PST, deleted the AD account and Exchange mailbox and then rebuilt them. I then imported the PST. External mail is still not coming to the user.
Mail is not even hitting the mailbox. Checked OWA.