I have two computers using Thunderbird. We have Bellsouth.net as our carrier (using ATT servers). Both computers have the same 5 bellsouth addresses and 4 of those work well. But a couple days ago the 5th, in trying to get messages, continually comes back stating unable to access server. This is true on both computers. I have checked so many things over the past 2 days, including password (even changing it just to see if that would help) - and I can get our messages using the same password by going to ATT online. There just seems to be a snag for that one address to be blocked from getting its message. Here is the statement on the screen: "Sending of password for user did not succeed. Mail server inbound.att.net responded: Server error- please try again later". Well, later seems to be permanent. And why would it be a password problem when that same password gets us to the mother computer online? Hope you have some suggestions. Thank you very much. Bob