How to deal with exim4 errors, messages not being sent?

Question

linux

Today I removed such a horror with errors from the Exim 4 logs

2016-01-15 06:49:58 TLS error on connection from [мой ip] (recv): A TLS fatal alert has been received.: CA is unknown
2016-01-15 06:49:58 TLS error on connection from [мой ip] (send): The specified session has been invalidated for some reason.
2016-01-15 06:51:49 Start queue run: pid=15747
2016-01-15 06:51:49 End queue run: pid=15747
2016-01-15 06:51:58 TLS error on connection from [мой ip] (recv): A TLS fatal alert has been received.: CA is unknown
2016-01-15 06:51:58 TLS error on connection from [мой ip] (send): The specified session has been invalidated for some reason.

And I just tried to log in through Mozilla Thunderbird. Settings and config automatically builds a panel for Ajenti hosting.
For the sake of fun, I indicated the mail.ru server in the smtp mozilla created an account and receives messages (only it doesn’t send =) )
Through Rainloop, it also sends and receives, including via ssl.
It was working yesterday.
I suspect it's Exim.
Who as met with such prompt.

Answer 1

CA is unknown
he doesn't like the certificate

Answer 2

You are most likely using a self-signed certificate. Set the root certificate in Mozilla to the trusted list and allow its use.