Issues with mail delivery after changing primary SMTP address.

[Jaycee]

I had a user with 2 smtp email addresses. The secondary email address was
set as the primary and the old primary address was removed.

Before:
SMTP:[email protected]
smtp:[email protected]

After:
SMTP:[email protected]

Now when and external email is sent to (e-mail address removed) the email is
underliverable and states that the (e-mail address removed) account does not exist.
Internal email to this address works fine.

Any ideas?

Thanks.