How to Set Up Lion E-Mail Server
Mail Server is unique in Lion Server in that it is the only service that is configurable from both the Server app and Server Admin. In fact, you can use three tools to set up and manage mail service in Lion Server. You can use one of them or all three. Here are the three tools and what you can do with them:
The Server app: The simplest way to get e-mail running, the Server app offers a subset of available settings, automatically configuring behind the scenes. It lets you set up a relay to an Internet service provider to send e-mail to the Internet, but doesn’t enable you to create an MX record.
The Server app also lets you blacklist known e-mail servers (spammers), as well as filter spam and viruses. Turning on Mail Server with the Server app turns on SMTP, POP, and IMAP protocols, but doesn’t let you turn off either POP or IMAP. With the Server app, you can’t see what all the settings are.
Server Admin: Here is where you can see the full suite of settings. It gives you additional options for dealing with spam and lets you change settings for authentication. It also lets you set up mail lists, or listservs, and set maximum message sizes.
You can create MX records with Server Admin, as well as configure Mail server clustering, in which multiple servers act as one Mail server. But Server Admin has dozens of choices in lots of screens with little help to let you know what is what.
Configuration Assistant: The happy medium between the two other tools, Configuration Assistant takes you through a fairly detailed configuration with explanations of what you need to do and what the settings are.
Configuration Assistant is available only through Server Admin, however. Mail Server needs to be enabled before you can get to it. Enabling Mail Server in Server Admin is a multistep process. Enabling Mail Server in the Server app is two mouse clicks.
Therefore, a two-step method is the best way to set up mail service for the first time in Lion Server:
Turn on Mail Server with the Server app.
Configure with the Configuration Assistant.
If you later find that you need some more tweaks or you need to troubleshoot, then use Server Admin.