Linux Mail Server Setup and Howto Guide

Red Hat Enterprise Linux 5 and its derivative CentOS 5 includes a graphical tool called Security Level Configuration for configuring the firewall options. This article describes how to use the Security Level Configuration tool to open up the ports necessary for providing an email server.

1. Click System, select Administration and click Security Level and Firewall. This will launch the Security Level Configuration window.

2. For a mail server with webmail, check Mail (SMTP), Secure WWW (HTTPS) and WWW (HTTP) in the Trusted services list.

3. We also need to open the ports for the POP3 and IMAP services. In the Other ports field, add the port numbers below.

 

Service

Port

POP3

110:tcp

POP3S

995:tcp

IMAP

143:tcp

IMAPS

993:tcp

In text mode, use the system-config-securitylevel-tui command to do the same.

 

You can see the list of service and port numbers by typing in getent services from the Terminal window.

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Visit the forum to ask for help or to give a comment.

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Posted on 4/23/2007 and last updated on 11/7/2009
Filed under CentOS 5 , Red Hat Enterprise Linux 5 , System Administration

 

4 Responses to “Firewall Configuration Howto for RHEL/CentOS 5”

1. keshav:
   June 1st, 2009 at 1:35 pm

   i configured https,http, pop3,pop3s,imap,imaps,ssh from system-config-securitylevel,but when i try with the https://localhost:10000/ link no page showing

2. consultant:
   June 12th, 2009 at 3:48 am

   Hi keshav,

   I think you came from my Installing Webmin article. Sorry, I forgot to mention you have to start the httpd service. Please check my article again, I’ve already updated it.

3. jfox:
   August 7th, 2009 at 10:19 pm

   Is there a way to do this without the GUI?
   I have a VPS with shell access and no X server.

4. consultant:
   August 9th, 2009 at 7:03 pm

   Hi jfox,

   Try system-config-securitylevel-tui