Unable to send email to external recipients

[Sean]

Hi all, I've got a puzzling problem on one of my users'
systems. He is running Windows XP, Office 2000 on a Dell
PC. Pretty vanilla setup. He can send emails to any
internal recipients, i.e., those on the same internal
domain that he is on. However, when he tries to send to
an external address, for example (e-mail address removed), he gets
an undeliverable message error from Exchange, "Unable to
deliver the message due to a recipient problem". He is
the only user on my domain that is having this problem.
Any thoughts? Thanks!

 

[Sean]

In case anyone else runs into this issue, I figured out
the problem. Seems this particular account was set up
for some reason without an X.400 address configured.
Hence, public addressing would not work. Anyways, hope
this helps somebody.

-Sean