Skip to Main Content
Postfix: The Definitive Guide
book

Postfix: The Definitive Guide

by Kyle D. Dent
December 2003
Beginner content levelBeginner
278 pages
10h 47m
English
O'Reilly Media, Inc.
Content preview from Postfix: The Definitive Guide

Inbound Mail Gateway

A mail gateway is an email system that accepts messages and relays them to another system. Gateways might provide a path from one network to another, or from one protocol to another. A common use of a mail gateway is a server that accepts all the mail for a network from the Internet and relays it to internal mail systems. Mail gateways are commonly set up in conjunction with firewall systems to limit the number of servers that need direct access to the Internet.

Imagine a company network such as the one depicted in Figure 9-2. There are sub-domains for different workgroups at the company, and each workgroup has its own internal mail server. The gateway system gw.example.com receives all the mail for the network. The human resources department gets email addressed as user@hr.example.com, and their mail should go to the server mail1.example.com. The sales department uses user@sales.example.com, and their mail should go to mail2.example.com. The client hosts in each subnet retrieve mail from their respective mail servers. Transport maps are required to set up the mail gateway gw.example.com to relay messages to the correct internal mail servers.

Email gateway to internal systems
Figure 9-2. Email gateway to internal systems

The following procedure demonstrates how to configure gw.example.com to relay messages to the correct internal systems:

  1. Make sure that the DNS has been configured correctly with ...

Become an O’Reilly member and get unlimited access to this title plus top books and audiobooks from O’Reilly and nearly 200 top publishers, thousands of courses curated by job role, 150+ live events each month,
and much more.
Start your free trial

You might also like

Linux Cookbook, 2nd Edition

Linux Cookbook, 2nd Edition

Carla Schroder
Linux Under the Hood

Linux Under the Hood

Sander van Vugt
Kubernetes: Up and Running, 2nd Edition

Kubernetes: Up and Running, 2nd Edition

Brendan Burns, Joe Beda, Kelsey Hightower

Publisher Resources

ISBN: 0596002122Errata Page