I just read a line in my logfile that I haven't noticed before:

Aug 29 22:17:23 <myserver> dovecot[50098]: imap-login: Disconnected: Connection closed: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol (no auth attempts in 2 secs): user=<>, rip=104.152.52.31, lip=10.10.10.37, TLS handshaking: SSL_accept() failed: error:14209102:SSL routines:tls_early_post_process_client_hello:unsupported protocol, session=</w+MZ7jKvLhomDQf>

Is this a TLS 1.3 related issue?

/elise