Sendmail problem

[Tim]

On Tue, 2014-08-05 at 10:37 -0400, Kevin Cummings wrote:
> Starting at some point during the day on July 30, my outgoing emails
> have been queueing up on my Fedora 19 server with some strange messages:
> 
> > # mailq
> > 		/var/spool/mqueue (1 request)
> > -----Q-ID----- --Size-- -----Q-Time----- ------------Sender/Recipient-----------
> > s75EJYwb013189*    3981 Tue Aug  5 10:19 <cummings at kjchome.homeip.net>
> >                  (Deferred: Connection refused by localhost.localdomain.homeip)
> > 					 <recipient at gmail.com>
> > 		Total requests: 1

Are you using domain names that you own?  Is there a DNS entry that
points to someone else's IPs?

Foggy memory, here, but sendmail may be looking up MX records to work
out where to send mail, and if there is a public record that doesn't
relate to your own IPs, things could be messy.  The hosts file cannot do
MX records.  You'd need to configure sendmail to know that certain
domains are local.

Email can be rather painful when you're using host files, I use a local
DNS server which has a configuration set into it for all local machines
in the same manner as is traditional for setting up real public IPs
(e.g. forward and reverse look-ups, A names for machines, CNAMES for any
aliases, MX records).

> And why is localhost.localdomain being prepended to my local domain
> name in the mqueue?

When there are multiple answers for domain names (host files, or DNS),
it's typically the first one that becomes the answer.

e.g. with the following in /etc/hosts

127.0.0.1  localhost  localhost.localdomain something.example.com
127.0.0.1  blah.example.com

All those domain names and hostnames have the 127.0.0.1 IP.  But if
something asks what's the name for 127.0.0.1, the answer will be just
"localhost".

-- 
tim at localhost ~]$ uname -rsvp

Linux 3.15.7-200.fc20.i686 #1 SMP Mon Jul 28 19:21:33 UTC 2014 i686

All mail to my mailbox is automatically deleted, there is no point trying
to privately email me, I will only read messages posted to the public lists.

George Orwell's '1984' was supposed to be a warning against tyranny, not
a set of instructions for supposedly democratic governments.