On 29/06/2021 07:50 Voytek Eymont <voytek@sbt.net.au> wrote:

I have a user failing to get mail , using TBird client

is this due to his TBird email client backlevel TLS support ?

I'm trying to find out his TBird version, might be an older TBird

# dovecot --version 2.3.15 (0503334ab1)

# egrep "ssl_protocols|ssl_min_protocol" /etc/dovecot/conf.d/10-ssl.conf

#ssl_min_protocol = TLSv1.2

Jun 29 14:23:27 pop3-login: Info: Disconnected: Connection closed: SSL_accept() failed: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol (no auth attempts in 1 secs): user=<>, rip= 111.222.333.555, lip=ser.ver.ip.add, TLS handshaking: SSL_accept() failed: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol, session=<kZ6p99/FW9iTMgHi>

Jun 29 14:23:54 pop3-login: Info: Disconnected: Connection closed: SSL_accept() failed: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol (no auth attempts in 1 secs): user=<>, rip= 111.222.333.555, lip=ser.ver.ip.add, TLS handshaking: SSL_accept() failed: error:140760FC:SSL routines:SSL23_GET_CLIENT_HELLO:unknown protocol, session=<Gq5G+d/Fu1STMgHi>

This seems like the client is trying to connect using STARTTLS to a SSL port. Or not using TLS at all.

Aki