Thank you for your reply. He is using his full email address. The security stuff is set to none. They gave me both options for smtpa  with port 2225 and smtp with port 25. We have tried both. How do we unlock a port?

I am trying to help my father (long distance) set up his email options after he moved. Pegasus mail was working fine before this for years!!!

I called his ISP and got the settings. We have managed to receive mail but still cannot send.

They said the outgoing server host name was smtpa.bellaliant.net, use port 2225, then I had him enter his email address and password into the security tab "log into the SMTP server using the following details:" We have checked and rechecked ...

If the configuration instructions did not make reference to SSL, TLS, or StartTLS then make sure the option for the SSL/TLS settings in the Security tab is set to None. 

Also confirm that he is using his full email address for his username.

Finally, a web search found some conflicting information about whether the host should be smtpa.bellaliant.net or smtp.bellaliant.net.  That could be just typos but it might be worth testing with smtp.

If those aren't it, you may need him to have him create an internet session log and send it to you for analysis.  It should identify the point of failure.  I would test using the smtpa host name for the first go. Be sure he turns internet session logging back off.

One other thought.  I've never seen port 2225 used so wonder if it is a port that needs to be unblocked in the firewall.