Postfix Connection Timeout, CentOs

joeyadms · 05-18-2008, 04:47 AM

Well, me and mail servers just don't work out. I have been working on and off for about 3 years fooling with sendmail,postfix,qmail on several different unix/linux installs.

I am a web developer, and trying to get php's mail() to work. I am using postfix, and getting connection timed out in logs.

I am very happy with my current CentOS install and would really like to get this working.

I will first say what all I have done, then post the logs and conf.

Today I decided to get this working, I started off with Sendmail still installed. I used yum to install postfix and system-switch-mail, then used
system-switch-mail to switch over to postfix and restarted the machine.

Whenever I try to send mails from telnet or from php, they get connection timed out in mailq and maillog. I am certain it is my configuration, I have never understood it much, and have tried following almost every guide out there. I don't want to botch this install, so I am putting myself into your hands haha.

mailq-----------------

Code:

-Queue ID- --Size-- ----Arrival Time---- -Sender/Recipient-------
C9FD84500BF      332 Sun May 18 05:06:42  www@localdomain.localdomain
         (connect to gsmtp183.google.com[64.233.183.27]: Connection timed out)
                                         email@gmail.com

A45F34500B8      323 Sun May 18 04:54:32  www@localhost.localdomain
        (connect to gsmtp147.google.com[209.185.147.27]: Connection timed out)
                                         email@gmail.com

364B04500C6      366 Sun May 18 05:24:46  joey@joeyadams.net
         (connect to gsmtp183.google.com[64.233.183.27]: Connection timed out)
                                         email@gmail.com

E1DA84500B5      339 Sun May 18 05:21:01  www@localdomain.localdomain
         (connect to gsmtp183.google.com[64.233.183.27]: Connection timed out)
                                         email@gmail.com

maillog ----------------------------------------

Code:

May 18 05:40:58 localhost postfix/pickup[2537]: 015DF4500CB: uid=500 from=<www>
May 18 05:40:58 localhost postfix/cleanup[2879]: 015DF4500CB: message-id=<20080518094058.015DF4500CB@redhat.localhost.localdomain>
May 18 05:40:58 localhost postfix/qmgr[2538]: 015DF4500CB: from=<www@localdomain.localdomain>, size=339, nrcpt=1 (queue active)

main.cf -------------------------------------------------------
This is a long file, you can find it here
http://www.joeyadams.net/cf.txt

/etc/hosts ----------------------------------------------------

Code:

# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1               localhost.localdomain localhost
::1             localhost6.localdomain6 localhost6

/etc/sysconfig/network -----------------------------------------

Code:

NETWORKING=yes
NETWORKING_IPV6=yes
HOSTNAME=localhost.localdomain

Thanks ahead of time for any help.

datopdog · 05-18-2008, 07:24 AM

it seems like your system can not outbound connections on port 25, double check that on the command line i suspect your ISP is blocking your port 25 out and want you to use their mail server to relay all outbound email, if that is the case configure postfix as a smart host of their system

joeyadms · 05-18-2008, 08:04 AM

Well I have another server, Win2k3, that is my actual mail server. It can send out/receive mail.

datopdog · 05-18-2008, 10:21 AM

did you even try to test that you can connect to port 25 from that machine ? These are simple troubleshooting steps that will help you fix the problem, if you find that you cannot connect on that machine but can connect from your win2k system then there are possible causes you can look at

1. do u have a correct default route out ? can you ping internet systems ?

2. Is a host firewall on the linux machine blocking out smtp traffic ?

3. Is your router blocking smtp traffic from the linux host ?

4. You could have 1 to 1 nat for the windows machine which allows only that ip out on port 25

joeyadms · 05-18-2008, 02:00 PM

Hey thanks for the response. I don't have any firewall running, and my router doesn't have any restrictive rules.

BUT! I tried to telnet from my dev machine to the linux server, and could not connect, same thing from my windows server to the linux server.

Netstat -an says its listening on 25, and I can telnet from the linux server to localhost. However from the linux server I cannot telnet to the local IP address, it says connection refused.

I think we found our problem. Sounds like it's not allowing outside connections.

joeyadms · 05-18-2008, 02:49 PM

I'm an idiot, I forgot I was using iptables, I configured it to forward through, and now I can successfully connect from anywhere.

My Mails to sent to my win2k3 mail server /@joeyadams.net/ are sent fine, ones through google time out however.

I just tried other domains like yahoo, they won't send either.