I am occasionally using an e-mail server with out of date TLS settings. Unfortunately, there is no work around for one particular job that I have to do. When I first was updated to version 78, I got the error described in the string, "can not send mail after update ver78...." I updated my TLS settings as follows: security.tls.version.min = 1 security.tls.version.enable-deprecated = true And everything seemed to work. However, today, I can no longer send e-mails with that server. It appears that another update broke things again. I am currently running 78.10.1 on Windows 10. I can receive e-mail, no problem. With the bad server, a test message appears to be sent and gets put in the sent messages folder but doesn't show up in my inbox on another account. I'm not sure of the date but it appears that a message I sent on April 28 worked. I'm filing a bug report