Installing GFI MailSecurity in gateway mode

Introduction to installing in SMTP gateway mode

This chapter explains the procedure how to install and configure GFI MailSecurity in SMTP gateway mode. There are 2 ways to install GFI MailSecurity in SMTP gateway mode:

On the Exchange Server 2000/2003 machine.
On a separate machine at the perimeter of your network.

If you are installing on the Exchange Server 2000/2003 machine, set-up is very straight forward. Simply choose gateway mode rather then VS API mode.

If installing on a separate server, you must configure that machine to act as a gateway for all mail first. This set-up is also known as 'Smart host' or 'Mail relay' server. Once configured, you can install GFI MailSecurity on that machine.

In SMTP gateway mode, GFI MailSecurity checks inbound and outbound mail before it reaches your mail server. For more information about GFI MailSecurity operating modes and the SMTP gateway mode, please see the chapter `Explaining GFI MailSecurity'.

SMTP gateway mode is the correct mode if you run Exchange 5.5, Lotus Notes or another SMTP/POP3 server!

If you are running a Windows NT network: The machine running GFI MailSecurity can be totally separate from your Windows NT network - GFI MailSecurity does not require Active Directory!

Installing GFI MailSecurity in front of your firewall

A good way to deploy GFI MailSecurity is to install it on a separate machine in front of your firewall or on your firewall (if running a Windows 2000/2003 firewall such as Microsoft ISA Server). This allows you to keep your corporate mail server behind the firewall. GFI MailSecurity will act as a smart host/mail relay server in the perimeter network (also known as DMZ - demilitarized zone).

Additional advantages are:

You can perform maintenance on your Mail server machine, whilst still receiving email from the Internet.
You use less resources on your Mail server machine
The GFI MailSecurity machine can have a lower spec then the Mail server machine and process mail faster.
Additional fault tolerance - if anything happens with your Mail server you still receive mail, which is queued on the GFI MailSecurity machine.
Note: This separate machine does not need to be dedicated to GFI MailSecurity, it can be running other applications, for example a firewall.