I'm running Exchange Server 2010 in a xxx.local domain environment, and our accepted domain is xxx.com, which means our email address format is username@xxx.com. Now I can authenticate SMTP with username alone or username@xxx.local, but I cannot authenticate SMTP with username@xxx.com, not even OWA. Is there a way so that I can authenticate both SMTP and OWA with username@xxx.com? Please help. Thank You.

Is this a very difficult question? Can anyone help?

Hi, Did you try another user to do the testing Whether only one user has this issue? Thanks Allen