[CentOS] Mail has quit working

Fri Aug 24 16:07:40 UTC 2018
Pete Biggs <pete at biggs.org.uk>

> > OK. There are a couple of things:
> > 
> >    Aug 23 21:47:18 ts130 postfix/smtpd[3750]: warning: hostname localhost
> > does not resolve to address 127.0.0.1
> >    Aug 23 21:47:18 ts130 postfix/smtpd[3750]: connect from
> > unknown[127.0.0.1]
> > 
> > That needs to be fixed. What does the entry for 127.0.0.1 look like in
> > /etc/hosts? Have you also defined ::1 to be localhost in /etc/hosts?
> 
> 127.0.0.1	localhost localhost.localdomain localhost4
> localhost4.localdomain4
> 192.168.1.110	ts130.palmettodomains.com	ts130
> 192.168.1.110 mail.palmettodomains.com mail
> 
> # ::1         localhost localhost.localdomain localhost6
> localhost6.localdomain6
> 192.168.1.102	edukes1.palmettodomains.com edukes1
> 192.168.1.105	hp8200.palmettodomains.com hp8200

In the file /etc/nsswitch.conf there is a line that starts hosts: what
does that say?

> 
> > 
> > 
> >    Aug 23 21:47:21 ts130 dovecot: imap-login: Login: user=<tdukes>,
> > method=PLAIN, rip=::1, lip=::1, mpid=3754, secured,
> > session=<9W1yjiR08AAAAAAAAAAAAAAAAAAAAAAB>
> > 
> > So you are connecting over TCPv6 from roundcube to dovecot?  Is that
> > what you want?
> 
> I have IPV6 disabled (I think).

Well it's certainly trying to connect via v6 - that's what the ::1 on
that line is.

> 
> > What is the IMAP hostname in the roundcube configuration?
> > 
> > 
> $config['default_host'] = 'localhost';
> 
I think part of the problem is that 'localhost' is being interpreted as
the IPv6 loopback device ::1 and not the v4 127.0.0.1 - it may be that
roundcube has got a wrong mailhost stored. Try running the following
SQL command on your roundcube database:

 mysql --user=rc -p roundcubemail -e "select username,mail_host from users;"

It will prompt for the password. (Obviously use a different user if
it's not 'rc' and a different databasename if it's not 'roundcubemail'
- they are the defaults and are defined in the roundcube config file.)

It will come back with a list of the users defined and the mailhost it
will attempt to connect to for that user.

P.