I am trying to integrate one of our external systems with our outlook and it is asking me for SMTP server details. The only part that seems to be wrong is the Port No, where can I find this?
All of the port settings are found in the dialogue box for the email setup center.
For SMTP they typically are 80, 3535,25 or 465 (SSL). Some ISP's are very restrictive on allowing a "3rd party sender" so you may end up having to contact them to see what your specific configuration should be.
I had a client that had fits with ATT over this issue.
Hope this helps,