Balsa 1.2.3 installed and receiving but not sending

["amp " <amp foomonkey com>]

I finally got Balsa 1.2.3 installed and running.  It was not easy or pretty.  I started with RedHat 7.1.  I could not get everything installed and updated there so I upgraded to 7.2.  I'm sorry but, 7.2 just bites.  Nothing seems to work right.  I downloaded Mandrake 8.1 and installed it.   Then I downloaded and installed everything for Balsa and its dependencies.  

It is running and receiving mail but I will not send. I have tried setting the "Remote SMTP Server" to my ISP's mail server (mail.earthlink.net).  When I compose and click Send, I get the "Sending" dialog box but it will not send.

I'll check out the FAQ but I am hoping this is easy.

Thanks.
Andrew