Roundcube error:
Roundcube – Database error: Connection failed!

Exim log

Aug 17 01:52:44 206-225-82-31 dovecot: auth: Error: Cpanel::MailAuth: Failed to lookup domain owner of domain.com
Aug 17 01:57:44 206-225-82-31 dovecot: master: Warning: Killed with signal 15 (by pid=24147 uid=0 code=kill)"

Run:

# /usr/local/cpanel/bin/update-roundcube --force