Have Server running Windows Server Std 2003
Server is also Domain Controller (Has AD installed on it)
Server has Exchange 2003 installed and running
Have a single user that cannot receive external email
Same user can receive internal email no problem
Same user can send email out
When you send a message you get recipient not found, but she is there and so is her mailbox, as listed in AD and in Exchange System Manager>Admin Groups>First Admin Group>Servers>Servername>First Storage Group>Mailbox Store>Mailboxes>Her Mailbox
There are over 100 users on this system, all others working correctly.
Mailbox appears to be good
User account appears to be good (User logs in and works all day successfully, just no incoming email from outside)
Any ideas what the issue is and/or where to look?