Running: WIN 10 PRO FIREFOX 81.0.2 (64-BIT) THUNDERBIRD 68.121 (32-BIT) NORTON SECURITY 22.20.5.39 Xfinity ISP Ran Thunderbird for years without a problem until 2 days ago, I cannot send or receive email using Thunderbird from my pc or other devices. When attempting to get new mail, receive following: “Alert from account [email@comcast.net temporarily blacklisted IP Address”. Also receive following error message “Login to server imap.comcast.net with username [email]@comcast.net failed” Attached is screenshot showing both alert and error messages. I attempted several times “Retry” and re-entering password. All attempts failed! I can log on to Xfinity.NET on the internet via Firefox, retrieve, read and send mail from Xfinity.net website. I cannot do the same using Thunderbird. Attempted fixes to include: disconnect of Norton anti-virus/firewall, reset password on Xfinity, reset WINS to an earlier date, use a different modem, changed passwords, all failed to fix problem. I am not a technical savvy individual and really need help in solving this problem, can someone help me: • Who has “blacklisted” my email? Comcast, Firefox, Thunderbird, Norton, WIN 10? • What has caused this to happen? • What do I need to do rectify the problem and get Thunderbird working again? Greatly appreciate any assistance you can give me. Regards, Ed [email]@comcast.net