SUMMARY

This document covers some fundamental concepts for consideration when setting up or configuring a mail server.

DETAIL

Disk IO Subsystem
Note: The primary consideration in hosting any mail server is disk IO - as all mail servers can be very disk IO intensive when placed under load. Consider SCSI, SERIAL ATA or the fastest hard drives available if hosting large numbers of mailboxes.

Also keep operating system and page file on different physical disks; and consider RAID on mail file storage. Again - these guidelines should apply irrespective of which mail server is used.

Mailbox Purging
Need to minimise the size of mailboxes where possible. Server hosted mailboxes over 5GB can cause significant disk IO.

Mailbox Purging
Do not use catch-all mailboxes unless they are monitored and purged periodically.

Backups
At a minimum, keep daily backups of the Mail Enable\Config directory. This directory is not large, but contains all the information regarding domains, address maps, user logon information, etc.

General

• If configuring the mail server to send messages to the postmaster when a mailbox is over quota, be sure to check this mailbox regularly. It is best to get the server to bounce email messages when mailbox is over quota.
• It is advisable not to configure more than a couple of reverse DNS blacklists. A DNS lookup has to be made for each inbound email, which will affect performance under load (i.e. enabling 7 DNS blacklists will require 7 DNS lookups to be made).