Hey Proxmox cluster. running ISPConfig 3.2.7p1 pm01: panel, web01, mx1, mx2, ns1, ns2 pm02: webmail. The installation i followed, is the automated script. https://www.howtoforge.com/ispconfig-autoinstall-debian-ubuntu/ My webmail.server cannot connect to mx2.server, states "Connection to IMAP server failed". If i tail /var/log/roundcube/errors.log on webmail server this is what is logged.. Code: [06-Feb-2022 12:33:25 +0000]: <-------> IMAP Error: Login failed for [email protected] against mx2.tlwebservices.co.uk from 22.214.171.124. Could not connect to ssl://mx2.tlwebservices.co.uk:993: Unknown reason in /usr/share/roundcube/program/lib/Roundcube/rcube_imap.php on line 200 (POST /?_task=login&_action=login)</code> and on mx2.server, this is the output from /var/log/mail.log <code> Feb 6 12:37:38 mx2 dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=126.96.36.199, lip=188.8.131.52, TLS handshaking: SSL_accept() failed: error:14094415:SSL routines:ssl3_read_bytes:sslv3 alert certificate expired: SSL alert number 45, session=<--------------> Feb 6 12:37:42 mx2 dovecot: doveadm(184.108.40.206): Error: doveadm client disconnected before handshake: Connection closed It does state in that log.. sslv3 alert certificate expired Why would the cert have expired and not been renewed??