This problem existed a few months ago, has come back for some reason. I re-downloaded the latest version of Avast Free. Windows XP, most recent version of Thunderbird.
Check out this link.
Different user here. I’ve already tried the suggested remedy several times. It works for about 24 hours then I have to go through it again. I finally just unchecked the “Scan SSL connections” box in Mail Shield. It may not be the ‘school solution’ to the problem but it at least works consistently. There should be an easier way to fix this problem without having users digging around down inside SSL connection settings, at least in my opinion.
Yes, my only solution was to not scan my emails. Sad… 