Hello, my problem is related to Microsoft Exchange 2000 SP3.
Here is the error I am receiving:
PERM_FAILURE: SMTP Error (state 10): 550 No such user - psmtp
This error occurs on three of my users (2 which are new and 1 that was pre-existing). They can receive e-mail from internal sources successfully, however when trying to send an e-mail to any of these addresses from an external e-mail source the above error is received back in the sending accounts inbox. Any suggestions would be great, and I am not an exchange guru so keep it simple please.