Apple Mac OS X Server (Administrator’s Guide) - Manual (Page 373)

Mail Service 373
Where Mail Is Stored
The mail service keeps track of email messages in a small database, but the database does not
contain the messages. The mail service stores each message as a separate file in a mail folder.
The mail service stores its database file and folder of messages in the folder /Library/
AppleMailServer by default. You can change the location of the mail folder and database to
another folder, disk, or disk partition. You can even specify a shared volume on another
server as the location of the mail folder and database, although using a shared volume incurs
performance penalties.
Mail service uses an additional folder if you turn on the option to use an alternate mail
transfer agent, such as the UNIX Sendmail program. The alternate mail transfer agent delivers
mail for users of your Apple mail service to the /var/mail folder. This is the standard UNIX
mail delivery location. Mail for each user is stored in standard UNIX mailbox format in a file
with the user’s name. The Apple IMAP and POP service imports mail from this location to the
mail database in the /Library/AppleMailServer folder. A user’s mail remains in /var/mail until
the user checks for new mail. Technically, the Apple mail service imports a user’s mail when
the user selects the Inbox via IMAP or triggers a LIST via POP.
How User Account Settings Affect Mail Service
In addition to setting up and managing mail service as described in this chapter, you can also
configure some mail settings individually for everyone who has a user account on your
server. Each user account has settings that do the following:
m enable or disable mail service for the user account
m specify the server that provides mail service for the user account
m set a quota on the amount of disk space for storing the user account’s mail on the server
m specify the protocol for the user account’s incoming mail: POP, IMAP, or both
m maintain separate inboxes for POP and IMAP mail
m show a POP mailbox in the user’s list of IMAP folders
m alert the user via NotifyMail when mail arrives
What Mail Service Can Do About Junk Mail
You can configure your mail service to decrease the volume of unsolicited mail, also known
as junk mail and spam. You can take steps to block spam that is sent to your mail users.