I needed to renew the SSL Certificate. I followed the steps here
After restart IMAP Login (dovecot) is not working with the following error
dovecot: imap-login: Disconnected (no auth attempts in 0 secs): user=<>, rip=192.168.8.158, lip=192.168.8.12, TLS: SSL_read() failed: error:14094418:SSL routines:ssl3_read_bytes:tlsv1 alert unknown ca: SSL alert number 48, session=<7sP0y1e2jdfAqAie>
Seams like dovecot can not find the rootCA. Any hints what I can do to make dovecot and my users happy?
Thanks in advance