first time install: iRedMail
CentOS 7.2, iRedmail 0.9.5-1.
Restarting services and VM did not help.
Looked at:
/var/lib/mysql/server.err
/var/log/dovecot.log
/var/log/messages
/var/log/iredapd/iredapd.log
/var/log/fail2ban.log
/var/log/httpd/error_log