I have tried everything recommended to try and log into the ATT email website. What is weird is that the email is coming into Thunderbird just fine and I can log in using the Edge browser. I only log in to the ATT site every so often in order to mark emails as spam and occasionally to look in the spam folder for a missing email. I have deleted the cookies for this website and the history as recommended. I don't want to delete all my cookies as it is a real pain to have to log back in to all the sites I regularly use. I saw on a Microsoft site that this is a documented problem and sometimes changing one's password helps but I can't find a way to change my password. I'm no longer an ATT customer (after getting a better internet provider that ATT DSL!) but I still use that email address. I am baffled. Appreciate your help.