I've been following this tutorial : http://www.linuxmail.info/ to set a mail server on centOS 6. Everything was going fine until I reached this section : http://www.linuxmail.info/ . When I try and connect to my domain name via SMTP I get a connection refused but I've I use pop3 I connect to dovecot fine.

  • Check your logs and give us the error recorded, please
    – Dom
    Aug 8, 2012 at 15:37

2 Answers 2


There are more official-ish docs on the CentOS wiki:



Probably a few others.

There could be a number of things that are wrong. One in particular is your ISP blocking port 25 traffic as an anti-spam measure. In that case, you should be using the SMTP submission port (587) for Postfix, or SMTPS (SSL-enabled SMTP) on port 465.

Verify that Postfix is listening to the public interface, e.g., netstat -pant |grep ":25".

If it's a SASL authentication issue, check your logs.


From the netstat output in the comments, it looks like Postfix is only listening to localhost.

Look at CentOS Wiki's Postfix configuration guide for the available options. In particular, you want to set inet_interfaces = all from whatever the default is in /etc/postfix/main.cf and reload.

  • tcp 0 0* LISTEN 15363/master Aug 8, 2012 at 15:44
  • Ah, it's only listening on localhost. In that case, you should have an entry in main.cf like inet_interfaces. Set it so that you have inet_interfaces = all. Check wiki.centos.org/HowTos/… for more details.
    – cjc
    Aug 8, 2012 at 16:00
  • lol, I uncommented it and left the localhost one uncommented aswell. Can connect to it fine now, thanks :) Aug 8, 2012 at 16:07

doublecheck mynetworks you should include here your local network with netmask or the server probably will relay only emails from localhost

mynetworks =
smtpd_sasl_type = dovecot
smtpd_sasl_path = private/auth
smtpd_sasl_auth_enable = yes
smtpd_recipient_restrictions =  permit_mynetworks, 
broken_sasl_auth_clients = yes
  • Yeah, they're all there. Aug 8, 2012 at 15:53
  • what about your firewall? Does it allow traffic from external?
    – tombolinux
    Aug 8, 2012 at 16:04

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