App. Problem. Mac Mail

App. Problem. Mac Mail

Hi, my 1st post, hopefully the beginning of many more.

I have a problem "sending" in the Mac Mail App (ver 2.1) OSX 10.4.8
I've done all the applicable procedures recommended by Apple at their support site but it has not helped.

Furthermore, I've deleted:
*Users>Library>Caches and Mail folder
*Users>Library>Mail folder
*Users>Library>Mail Downloads folder
Users>Library>Preferences>com.apple.mail.plist file
*System>Library>Mail folder

*(actually, I made duplicates and dragged them to a safe location away from any Library access)

I've deleted my .mac account in the Mail preferences (but it keeps coming back)

All this time, I HAVE been able to receive mail without a problem.
The ONLY time I can send mail from the App. is when I have mail in my "outbox" and I delete the Users>Library>Preferences>com.apple.mail.plist file. After deleting this file, I start the Mail App. and it sends the mail no problem. But to send more mail is impossible.

As well, I've tried using other mail programs: Opera, and Entourage but experience the same problem.

Any suggestions or solutions? I really hate using the Apple server to send/receive mail.

Thanks in advance!

Peter