On TB v78 the minimum requirement for SSL has increased and probably your email service provider still uses deprecated security for the mail server. Can you try to set lowest security by following the below steps and let us know how it works? From the menu at the top right, go to Options. Scroll all the way to the bottom and click on Config Editor -> Skip past the warning. Scroll down until you find security.tls.version.min (or paste security.tls.version.min to upper frame) Change the value 3 to 1. Restart TB. If it's still not working you may have to change the preference security.tls.version.enable-deprecated to true

Yes it works. Thank You very much

You should contact them on this regards though to updated their SSL to 1.2. and after that change back to 3 on TB...