We will start with the most basic components of an e-mail system. Together they will allow your users to receive mail from each other and from other people on the Internet, and send messages to whomever they want. This might be all you need, but many companies also want to provide their users with an accessible webmail service that people can use from home or when they are on the road. Another feature that many people unfortunately cannot be without today is proper protection against viruses spread via e-mail as well as filtering of spam messages.

This book will not cover all aspects of the software in question, but it will give you a solid ground to stand on and from there you will be able to delve into the more detailed descriptions of more advanced setups found elsewhere.

As the technical platform for our endeavor, we have chosen the GNU/Linux operating system and a proven selection of free software tools that will help us achieve the goal of a reliable e-mail server for the smaller company. The tools we have chosen are widely known and accepted, written by software professionals, and are supported by a large community of users.

In this very first chapter of the book, we start with what you need to know before you even start working on your server. Questions such as what kind of server hardware and network connection you need will be answered. We will also give you a brief introduction to internet e-mail and its working.

• Chapter 1: Linux and Email Basics
   
  • Why Manage your own E-Mail Server?
  • What you need to Host an E-Mail Server
  • Sizing the Hardware of your E-Mail Server
  • Main E-Mail Protocols—SMTP, POP, and IMAP
    • Overview
    • POP Protocol
    • IMAP Protocol
    • The SMTP Protocol
  • E-Mail and DNS
    • DNS Record Types Used by E-mail Applications
  • Backup Mail Servers
  • Development
  • Summary