One of the truly remarkable things about Postfix is that, in many cases, it works as soon as you install it, with little or no change to its configuration. In the first section of this chapter, we'll walk through checking the configuration and starting Postfix for the first time. Later sections discuss Postfix configuration details.
By default, Postfix is configured as a traditional Unix mail server, sending and receiving messages for all the accounts on the system. Your users can send and receive messages using any email client software available on your system.
In most environments, Postfix works in conjunction with a variety of other software systems. You should build each piece of your email system and test each one as a separate module before trying to integrate them all together. As you add each module, test the system before moving on to the next piece.
At this point you should have Postfix installed on your system. You might install Postfix from a packaged bundle for your platform or compile it yourself. See Appendix C for help with compiling Postfix, if you're building it yourself. Check your normal software sources for any Postfix packages that might be available. If you haven't yet installed Postfix, either get a package for your system or follow the instructions in Appendix C to build it. When you have finished with the installation, come back to this chapter for the final configuration.
I will assume, in examples throughout the book, that your installation of Postfix uses the default directories:
Configuration files and lookup tables
I will also assume that you or your installer created a postfix user and postdrop group. This user and group should not be used for any other purpose on your system. If you have changed any of the defaults, or if your Postfix package did, keep that in mind when you read the examples presented in the book.
General Configuration and Administration
Email and DNS
Local Delivery and POP/IMAP
Hosting Multiple Domains
Blocking Unsolicited Bulk Email
Transport Layer Security
Appendix A. Configuration Parameters
Appendix B. Postfix Commands
Appendix C. Compiling and Installing Postfix
Appendix D. Frequently Asked Questions