Outlook 2002 - Use only 1 SMTP server for 2 POP accounts.

[Gord]

I have 2 POP/SMTP accounts. They each require different
logon and passwords. When I send email, Outlook tries to
use both SMTP servers and I recieve an error message from
my second SMTP server account that my email was not sent?
My ISP does not allow the use of other SMTP servers on
their network. Is there a way to tell Outlook not to use
the second SMTP server? It will not let me leave that
field empty. Or do I have to organize the accounts
differently?
Thanks in advance.