Best practices for POP3 service

Applies To: Windows Server 2003, Windows Server 2003 R2, Windows Server 2003 with SP1, Windows Server 2003 with SP2

Best practices

Because the mail store can potentially use large amounts of disk space, you should either set a disk quota limit on the volume of the mail store (to control its disk space usage) or set it to use a volume other than the one where the operating system is installed. This will prevent the possibility of the operating system running out of disk space if the mail store becomes too large. For more information, see Set the mail store. For more information on disk quotas, see Configuring disk quotas for the POP3 service.

When an e-mail is undeliverable, the Simple Mail Transfer Protocol (SMTP) service returns it to the sender with a non-delivery report (NDR). If the NDR cannot be delivered to the sender, a copy of the message is put in the Badmail directory. To prevent the possibility of the operating system running out of disk space (if the Badmail directory becomes too large), you must move the SMTP Badmail directory to a volume other than the one on which the operating system is installed.

NTFS file system partitions provide greater directory and folder security. This enhances the protection of e-mail stored on the local hard disk.
Disk quotas can prevent the mail store from using an excessive or unanticipated amount of disk space. This is important because excessive or unanticipated use of disk space can adversely affect the performance of the server on which the POP3 service is running.

To ensure that you allocate adequate disk space for the mail store, estimate the amount of disk space it will need based on the number of users on the server, the volume of e-mail they will receive, and the average size of the e-mail they will receive.

Strong passwords protect your mail server from unauthorized access. For more information about passwords, see Strong passwords.