Did you verify the server is listening on 0.0.0.0 and that your
firewall is not blocking?

tcp        0      0 0.0.0.0:993                 0.0.0.0:*
     LISTEN      2325/dovecot
tcp        0      0 0.0.0.0:995                 0.0.0.0:*
     LISTEN      2325/dovecot
tcp        0      0 0.0.0.0:110                 0.0.0.0:*
     LISTEN      2325/dovecot
tcp        0      0 0.0.0.0:143                 0.0.0.0:*
     LISTEN      2325/dovecot

On Tue, Jul 10, 2018 at 11:17 AM, John Rowan <john.j.rowan.jr@gmail.com> wrote:
> I guess I've been lucky.  My Red Hat server I built in 2003 finally gave up
> the ghost yesterday.  Fifteen years with almost zero problems running 7x24.
> Now I'm trying to build a basic server to host my e-mail using CentOS 7,
> Sendmail and Dovecot.   Server is running great as are Sendmail and Dovecot
> but Dovecot only allows connections from the CentOS 127.0.0.1.  I can telnet
> localhost pop3 and get a +OK Dovecot ready response.  Trying to telnet from
> a different computer on same LAN times out.  I've looked at my old Dovecot
> config files to see how I enabled LAN IP access but the configs have changed
> a lot since I last installed Dovecot.  Googling hasn't helped.  Anyone help
> with a sample config with LAN IPs permitted?