Hello, I have been using an IMAP account till 2 month ago and it worked ok. It was setup to use SSL/TLS on port 993 and was working. I did not notice any error until few days ago and realized it hasn't been working for 2 months. I accessed it and saw it was unable to sync and subscribe to folders. I checked ISP settings suggested for it and they have not been chanhed. I tried to use no security and port 143 and it works. I used other Mail clients and they are able to use SSL/TLS on port 993. Just One of the many I tried automatically selected Legacy SSL/TLS, but all of them are working on port 993 except Thunderbird.