Hi Passwords for email are managed by your email server, not Thunderbird. What that means is, you need to set Thunderbird to use the same password that your email server expects, so that Thunderbird is allowed to fetch your messages. If you change your password using your email online - webmail with the provider - then you need to set Thunderbird to use the same password. If you change your password in Thunderbird, you must change the server / webmail password to the same password at the same time, or it won't work. So did your BTInternet password change? If not, set Thunderbird back to using the BTInternet password. Agnes

I had reset my password. When failing to connect, it asked me for a new, different password.I entered in the new one, ticking 'Use Password Manager to remember this password'. Unfortunately, Thunderbird still couldn't connect; I checked the password was correct (Options -> Passwords) and it was but it still wouldn't connect.

Well, that is a very unhelpful server error. Does it give any more details? It seems to come from BT server, and it might be a glitch at their end. It says TEMP, which may indicate that it is temporary and will go away eventually. Meanwhile, use webmail instead. I have seen it suggested online that if you log in to your BT email account online, and then open Thunderbird while still connected to webmail, that seems to fix Thunderbird's connection. Strange, but who knows... Here are some other links to people using different mail clients and getting a similar error from BT in the past. Do these seem the same symptoms you are seeing? https://community.bt.com/t5/Email/BT-Yahoo-mail-not-working-with-MS-Outlook/td-p/1927909# https://community.bt.com/t5/Email/Error-sys-temp-internal-server-error-iS6532/td-p/1703079# The theme seems to be not to change things as that may make it worse if the problem really is with a BT server.

OK, no worries Thank you