Question about Outlook Express

I'm using Windows live Mail on an eight-month-old computer running Windows 7 64-bit. It seemed to be doing just fine until my dial-up BellSouth/AT&T Internet account instructed me to change my inbound and outbound mail settings from the old BellSouth servers to new AT&T servers. After struggling for weeks to get the new settings to work, I still have one set of problems which is making my mail a nightmare to use. I'm constantly getting the error message:

"Unable to send or receive messages for the Bellsouth account. Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity.

Server: 'inbound.att.net'
Windows Live Mail Error ID: 0x800CCC0F
Protocol: POP3
Port: 995
Secure(SSL): Yes"

I think because my e-mail can never finish downloading, I'm getting a second problem: I'm constantly getting the same messages flooding my inbox over and over until there are hundreds of each one. I've had this problem at times in the past with other computers using mail programs I'm more familiar with like Microsoft outlook. I I have gone directly into my AT&T account many times now deleting messages hoping that there's one that's screwing up Microsoft live, but it never fixes the problem. Going into my e-mail account with my browser is also a problem, because for some reason about half the time whenever I try to login, the browser window (Internet Explorer 9) simply closes! The AT&T website where I check my mail is the only one that does this. It's maddening!

I'm spending 90% of my computer time now desperately deleting messages out of both Microsoft live and directly from AT&T. The only thing I know to do in the Microsoft Live settings is under the advanced tab where I've increased my server timeouts to first 3 min. and then 4 min. Under delivery "leave a copy of messages on server" is currently unchecked, but I've tried it both ways and neither seems to make any difference.

If someone out there can help me I would be so grateful. I feel like I'm on the edge of losing my sanity over this. I'm losing many hours that I can't afford to lose, and I'm almost ready to throw this computer that I desperately need out the window! Thank you.