To enable the mail service, open Server Admin and click on the name of the server in the Server Admin sidebar. Then click on Settings in the Server Admin toolbar (horizontally at the top of the Server Admin window) and click on the Services tab. Click on the checkbox for the Mail service and then click on Save.

The Mail service will appear under the name of the server. Click on the service and then click on the Overview button in the Server Admin toolbar. Click on the Configure Mail Service… button to bring up the Service Configuration Assistant for the mail service, which will guide you through the setup of a mail server.

At the Introduction screen, a list of technologies that comprise the Mail service is shown (e.g., Postfix, Dovecot, Kerberos, Mailman, etc.). Click on Continue to proceed to the Mail Service: General screen. Here, use the first three checkboxes to enable each protocol used in your environment. These include the following:

For most modern environments, IMAP and SMTP will be all that is required. Provided the mail server will be used to accept mail, also configure the following options (as shown in Figure 6-2):

Once you are satisfied with your options, click on the Continue button.

Figure 6-2. Configuring mail services

At the Mail Service: Filters screen are options to check mail for spam and viruses (Figure 6-3). The options for each are as follows:

Click on the Continue button, once the options are appropriate for your needs. You will then be looking at a bunch of checkboxes on the Mail Service: Security screen (Figure 6-4). Here, you are simply choosing which protocols the mail server will use. By default, these are secure (requiring SSL certificates). Unless you need to add POP access, leave them as they are, as any protocol not enabled during the setup assistant can be enabled once complete.

Figure 6-3. Configuring message protection

Figure 6-4. Enabling protocols

Click on the Continue button and you will be taken to the Mail Service: Mail Storage screen. The default location of the mail store (or the directory that all of the email is stored in) is /Library/Server/Mail/Data/mail, as you can see in Figure 6-5. If you will be using an external storage array, such as a Thunderbolt drive, then you can choose to use a mail folder stored there by unchecking the “Use default mail store location” box and then using the Choose button to locate the desired alternative location. Additionally, the Local Host Aliases section at the bottom of the screen can be used to add additional names to the mail server (e.g., if you use a name other than those listed to access the mail server).

Figure 6-5. Setting the path to the database

Click on the Continue button and then review the settings that will be used at the Mail Service: Confirm Setup screen. If they are as intended, click on the Continue button to finish setting up your mail server.

Once the assistant has completed, the services are configured. You can then more finely tune each service from Server Admin if you need anything that wasn’t configured by the Assistant. This might be mailbox quotas, who can relay (or send) mail through the server, mailing lists, and various degrees of what gets logged. A common feature to enable that isn’t covered in the service configuration assistant is mail quotas.

To enable mail quotas, open the Server Admin application from /Applications/Server and click on the Mail service in the Server Admin sidebar. Then click on the Settings icon in the Server Admin toolbar (which runs along the top of the window) and click on the Quotas tab. Here, you will see a number of settings (seen in Figure 6-6) that include the following:

Figure 6-6. Managing quotas

Quotas are then configured per user in the Workgroup Manager application (covered in Chapter 2). The Mail tab provides an option for setting the quota for each user. As many environments have a lot of users, you can use the Command key to select multiple users and set their quotas concurrently.

The configuration options in Lion Server also include automatically clustering the mail service. This is pretty cool for really large environments, as you can add multiple mail servers to the cluster as environments grow. Such a feature is only required in very large environments, and even with the sleek assistant to leverage when clustering, administrators still need a fairly advanced knowledge of managing large scale messaging environments to fully implement the functionality.

Once the mail server has been set up, you will need to create email accounts. Email accounts can be created in the Server Application or using Workgroup Manager. To create an account, open the Server application (e.g., by using LaunchPad) and click on Users in the ACCOUNTS section of the Server sidebar. Then click on the plus sign (“+”) to bring up the New User window. At the New User screen, provide the following information:

Click on Done to create the new user account. The user will then have the email address provided in the Email Address field, provided that the domain used in the email address (e.g., oreilly.com) matches a domain local to the mail server.