Hi, I have Norton360 as an anti-virus. When I( try to get messages, I get the attached Norton response. Checking with Google for a solution, I learned that my anti-virus package was involved, so I uninstalled Norton. I then got the attached Windows Defender message. With both package giving approximately the same message, and seeing the certificate with a June date, which is when the problem started, I wonder if the problem could be due to obsolete data remaining in Thunderbird. What do you suggest I try?