[CentOS] Mail has quit working

Fri Aug 24 11:57:36 UTC 2018
Pete Biggs <pete at biggs.org.uk>

> I have removed DNS3 from ifcfg-eno1 and set ONBOOT=no in ifcfg-
> enp1so0, reboot and still can't read mail. Logging into roundcube
> either times out or if I get in, the inbox is empty.
So, again, what do the dovecot logs say? 

How is roundcube setup? Specifically what is the IMAP server set to?
Remember, if you have changed the server definition in the config, the
individual accounts that were already defined in the database will
still have the old server definition.