In this section, some of Postfix's features for address rewriting to allow hosting multiple domains and implementing group addresses (or distribution lists) will be discussed.
Additionally, this section will take a look at how to find information in MySQL databases using Postfix. The goal of the exercise will be to use MySQL lookups for alias lookups, but the knowledge you can gain will be applicable for all other situations where you might want to use MySQL together with Postfix. It will be assumed that you have basic SQL knowledge and that you are able to set up and operate a MySQL server.
As was explained earlier, even though you can have several local domains (several domains listed in mydestination
), they will always be equivalent—they share a single localpart namespace. In other words, [email protected]
is [email protected]
is [email protected]
. Obviously, this is not good enough. In order to host multiple domains...