Add a new TCP/IP address
1) Add a new TCP/IP address to your system. Make sure
that Qmail is not using it, by telnetting to port
25 of that TCP/IP address. There should be no connection
accepted when you try this telnet command.
2) Add a DNS 'A' record for this new TCP/IP address, for example:
Install and Configure Hexamail
1) Install Hexamail
2) You will now need to set the SMTP Server setting in Hexamail. If you are installing Hexamail on Windows, the setup program will ask you for the TCP/IP and port of your mail server during the configuration Wizard, or you can change this by opening the administration interface and setting the port on the SMTP Server settings page.
3) Next, set Hexamail SMTP Relay settings to point to your newly configured port.