I'm not sure, but I think I have the most recent update to Thunderbird. A few days ago, I lost the ability to access my email thru Centurylink. The mail server is mail.q.com. My wife lost the ability to access her q.com email, also. I was able to restore her email by deleting the account and adding it as a new account. I tried that with my account, but it didn't work. The current settings are: POP3, mail.q.com, port 995, SSL/TLS, normal password. Whenever I try to get messages, I get an error box stating that the sending of the username failed. I tried to log in to email on centurylink.net, using the same user name and password I have for Thunderbird, and the log-in works normally. I can see all the missing emails on centurylink.net. I have tried every combination of POP3/IMAP, server port (110/995), connection security, and authentication method. Nothing changes. I still get the log-in failure. I spent 45 minutes on the phone with Centurylink. They recommend POP3, port 995, SSL/TLS, and normal password as the incoming server settings. Once they found I could log on through the Centurylink.net website, and discussed all the changes I made to the settings, they concluded it was a problem with Thunderbird. Since this has only recently started, after several years of successful log-ins, I am wondering if it has to do with the latest update. I'm at a complete loss as to how to correct the problem. I'd appreciate suggestions. JC