I am running mac os X version 10.3.5 and I find that mail will download not all my mail and will not send from any of my mailboxes.
I have set up mail with my googlemail account my mobileme account and my yahoo accounts. all are set up as stp and I have set them up according to all the online help lines. I have had mail set up for many months now, and have been trying to fix this problem for a long time now off and on.
One thing that I have tried is changing the outgoing port number from the default to 587, but still no joy.
Hope that someone can help.
— Jim Harrison