This issue is occuring on a box running:
Windows 2000 Server SP4 with Exchange 2000 SP3 and all critical updates applied.
I have a third party software that has email capability (progress reports) and attempts to send email by MAPI.
On my Win98 and W2k machines I am getting an error that either the Exchange server has the wrong name or the Internet cannot be found.
On my WinXP machines I can send the messages after I agree that viruses may be in the messges.
The third party software has worked well in past.
This morning the Application log had many incidences of
Source : MSEXCHANGESA
Cat : MAPI SESSION
Event ID: 9175