[Dovecot] After restart dovecot do not serves IMAPS anymore

I had to restart computer yesterday and now Dovecot has strange behaviour.

Dovecot is running and should serve IMAPS, but client Mozilla Thunderbird cannot connect.

I tried openssl s_client -connect localhost:993 and it said only CONNECTED(00000003).

A time ago when everything was OK, the listing after connection was "a bit" longer than it is now.

I remember there was "OK, dovecot ready" or something like that. Now, there is none.

Of course in /etc/dovecot.conf: protocols = imaps imaps_listen = * ssl_disable = no

So, what's the problem?