OS X 10.5.1 and BT email settings nightmare

[Willis]

Cant seem to get my OS X mail to send emails, can receive them no problem. I'm with BT and spoke to them but they are as useful as a choclate teapot. Its about my out going mail server which is mail.btinternet.com anyone else had problems with this and if so any ideas.

 

[Willis]

Turn on "Require authentication" on the outgoing server and use port 587.

I could kiss you thanks