Hi I followed this guide by falko: [Virtual Users And Domains With Postfix, Courier, MySQL And SquirrelMail (CentOS 5.3 x86_64)] Great guide! I set up this mail server on 10.10.0.200. I have a production webserver on 10.10.0.54. The gateway for both these servers is at 10.10.0.51. Above this gateway in the hierarchy is a firewall. For some reason, the gateway can't forward port 80 to the webserver and port 25 to the mail server. it is a one to one mapping. So whatever packets (be it http or smtp) arrive at the external ip, they are all forwarded to the webserver at 10.10.0.54. After I set up the mail server using the guide above, i was able to send out email, but not receive. Of course, because port 25 packets weren't reaching the email server. So I fixed this problem by using iptables prerouting and postrouting commands on the webserver. Basically I forwarded I port 25 packets arriving at the webserver to the email server. Now my squirrelmail is installed on the mailserver as well. How to access this from the outside? There are websites from being served on the webserver at 10.10.0.54, so I can't just forward port 80 to the email server. I was thinking to install squirrelmail on the werbserver at 10.10.0.54. How will I configure it to connect to courier on 10.10.0.200 ? Also, I have four websites running on my webserver, so i want all of them to access their mail by going to mail.domain.com. By default, squirrelmail is accessed by going to www.domain.com/webmail. I probably can set up a subdomain using apache virtual host directive. but i will need to change some setting in squirrelmail.conf under /etc/httpd/conf/cquirrelmail.conf. what would that be? I am a bit lost, please guide me. I thank you all in advance for all ur help.