When trying to send an email, I get the error message "cannot connect to output server IMAP", and it suggests making a retry (which simply repeats the same sequence). I have checked that my emails can be sent from the BT mail facility so the problem must be within the Thunderbird software. I see that other Thunderbird users have also encountered this problem which has suddenly arisen after my many years of successful use of Thunderbird. Can this problem be easily fixed and if so when is it likely to be fixed? I am an appreciative user of Thunderbird and look forward to an early solution.