An update to thread
http://forum.centos-webpanel.com/index.php?topic=8489 , seeing as it has been locked.
My previous quote:
Alternatively, if your installation has the official Configserver Firewall GUI.. 
Go to Firewall Configuration..
SMTP_ALLOWGROUP = mail,exim,postfix,dovecot
(not all will be required)
It is sufficient to just have..
SMTP_ALLOWGROUP = mail,postfix
.. assuming you don't use mailman (you shouldn't!) and you're looking to allow CWP server messages to be sent.
Topic: 25: Connection Refused (Read 2758 times)
