Apple Mac OS X Server (version 10.2.3 or later) - Manual (Page 431)

Mail Service 431
Performance Tuning
Mail service needs to act very fast for a short period of time. Mail service sits idle until a user
wants to read or send a message, and then it needs to transfer the message immediately.
Therefore, mail service does not put a heavy continuous demand on the server; it puts
intense but brief demands on the server. As long as other services do not place heavy
continuous demands on a server (as a QuickTime streaming server would, for example), the
server can typically handle several hundred connected users.
As the number of connected mail users increases, the demand of mail service on the server
increases. If your mail service performance needs improvement, try the following actions:
m Adjust how often mail service updates its DNS cache. For instructions, see “Updating the
DNS Cache in Mail Service” on page 420.
m Adjust the load each mail user can put on your server by limiting the number of
connections each user can have on a single IP address. For instructions, see “Controlling
IMAP Connections Per User” on page 409.
m Specify how long you want to allow IMAP mail connections to remain idle before the
connection is terminated. For instructions, see “Terminating Idle IMAP Connections” on
page 409.
m Move the mail storage location to its own hard disk or hard disk partition. For
instructions, see “Specifying the Location for a New Mail Database” on page 416 and
“Moving an Existing Mail Database” on page 417.
m Run other services on a different server, especially services that place frequent heavy
demands on the server. (Each server requires a separate Mac OS X Server license.)
Backing Up and Restoring Mail Files
You can back up the mail service data by making a copy of the mail service folder. If you need
to restore the mail service data, you can replace the mail service folder with a backup copy.
The mail service folder contains the following items:
m MacOSXMailDatabase, which is the mail service database file
m AppleMail, which is the folder that contains a file for each mail message and a file for each
mail account
These items are stored in the folder /Library/AppleMailServer unless you specify a different
location. For instructions on changing the mail folder location, see “Specifying the Location
for a New Mail Database” on page 416 and “Moving an Existing Mail Database” on page 417.
Important Stop mail service before backing up or restoring the mail service folder. If you
back up the mail service folder while mail service is active, the backup mail database file may
be out of sync with the backup AppleMail folder. If you restore while mail service is active,
the active mail database file may become out of sync with the active AppleMail folder.
LL0395.Book Page 431 Wednesday, November 20, 2002 11:44 AM