I have a secure email account that I have be able to access from Thunderbird (presently 38.5.1) since March 2015. In the last 3 weeks or so, I am sporadically getting this error message "Login to server imap.secureserver.net failed." I am using a verified password, and am able to access the email account via both webmail service and iPad. Just today, I got that error message for 45 minutes. Rebooted machine, restarted T-bird, no change. Whilst writing this note, the login succeeded, email downloaded to T-bird. When trying to send a reply, however, the problem reappeared. After re-entering the same password twice, the login succeeded. I'm at a loss.