eM having trouble sync with att/bellsouth

I have bellsouth/att internet my em client has to be reset not sure why and keeps asking my password I thought it may be att/bellsouth I can go on their sight and look at mail using the credentials that I have saved on eM but will not sync why? Could it me that they are not liking each other

Please help

Can you make sure that username in eM Client is the full email address, not just the part before the @.

Also, can you check that you are using the following server settings:

Host: inbound.att.net
Port: 993
Security policy: Use SSL/TLS on special port (legacy)

Host: outbound.att.net
Port: 465 or 587
Security policy: 465=Use SSL/TLS on special port (legacy) / 587=Force usage of SSL/TLS.

If that does not work, disable your anti-virus and firewall and try again.