Trying to get mailx setup and running

Linux and Unix-Like Red Hat
1

Ive kind of been left on my own to get things working on a production linux box. Im happy because it gives me some true admin experience. But theres alot I dont know ...

Im trying to get mailx running. I can create an email, but it never gets delivered to my external email account.

I am running
Centos 6.4 Linux

Heres what Ive done/checked so far ..

server> mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
F09841A260F* 784 Thu Jun 27 07:11:51 popeye@server.localdomain
popeye@mydomain.com

B3FF31A2476* 784 Thu Jun 27 07:09:36 popeye@server.localdomain
popeye@mydomain.com

-- 1 Kbytes in 2 Requests.

++++++++++++++++++++++++++++++

I then edit /etc/nsswitch.conf to change
hosts: files dns to hosts: files

+++++++++++++++++++++++++++++++

server> mailq
-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
B3FF31A2476 784 Thu Jun 27 07:09:36 popeye@server.localdomain
(connect to xyz.mydomain.com[10.10.10.10]:25: Connection timed out)
popeye@mydomain.com

F09841A260F 784 Thu Jun 27 07:11:51 popeye@server.localdomain
(connect to xyz.mydomain.com[10.10.10.10]:25: Connection timed out)
popeye@mydomain.com

-- 1 Kbytes in 2 Requests.

+++++++++++++++++++++++++++++++

So I guess my next two part question is

  1. how can I confirm that port 25 is open on the server ?
  2. how can I determine that there isnt a firewall blocking port 25 ?

Thanks!

2

Dear popeye,

The best test would be:-

telnet server 25

Of course, it relies on the telnet client being installed. Perhaps you can:-

nmap -p 25 server

Do either of these help?

A refusal response suggest that the server is not listening, but the firewall is allowing traffic. A timeout will be firewall rules.

Robin
Liverpool/Blackburn
UK

3

Seems the firewall isnt allowing 25.

Thanks for all the help !!