I am using Thunderbird 128.1 on windows 10. I am using SSL/TLS security on my POP connection. Due to a change, Thunderbird could no longer retrieve email over the secured connection. Thunderbird did not give any warning of this. Only after 16 days I found out no email was being retrieved. When I changed Connection security to "None" about 30 messages were retrieved. What setting do I change to make Thunderbird report a secure connection failure (possibly in the registry)? Thank you, Louis.