Mail store

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

Mail store

The mail store is a directory or Universal Naming Convention (UNC) path where the POP3 service stores all e-mail until users retrieve it to their client computer.

The basic structure of the mail store, or mail root, is a directory on the local hard disk where all e-mail is stored.

When a domain is created, the POP3 service creates a corresponding directory in the directory that has been designated for the mail store. For each user with a mailbox in that domain, POP3 creates a directory in the domain directory. E-mail that a user receives is stored as an individual file within the user's directory until the user retrieves it using a POP3 e-mail client.

The following is an example of the path to an e-mail message in the mail store:

C:\inetpub\mailroot\mailbox\example.com\P3_someone.mbx\P347865.eml

where mailroot corresponds to the mail store directory, example.com to the domain directory, P3_somone.mbx to the directory for a mailbox named someone and P347865.eml to a single saved e-mail message.

The directory and file permissions for each directory in the mail store are identical. When you configure the mail store, the permissions are set so that only local or domain administrators and the local network service, which the POP3 service is configured to run under, are assigned permissions to the directories. No other user is assigned read/write permissions.

The mail store's functionality depends on having adequate hard disk space available. To ensure the mail store's functionality, you should develop a disk-space requirement estimate based on the number of users on the server, the volume of e-mail that they will receive, and the average size of the e-mail they will receive.

In addition, you can protect the server from situations where the mail store's disk usage might increase unexpectedly by implementing disk quotas. Disk quotas monitor and control disk space that is used on NTFS file system volumes. For more information, see Configuring disk quotas for the POP3 service.

Notes

  • 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.

  • The mail store must be configured to use either a directory on the local hard disk or a UNC path; other storage options, such as mapped drives, are not supported.

  • You cannot set the mail store to the root directory of the hard disk, for example C:\, or to a directory in which files are currently in use.

  • If you restore the mail store from a backup or move it to a new location, you must reset the permissions on the mail store directory using the command-line procedure described in Set the mail store.

  • If you transfer the mail store to a new directory, you must move the mail store directory to ensure the directory retains the correct ownership; copying the mail store will not work.

  • Physical access to a server is a high security risk. To maintain a more secure environment, restrict physical access to the server where the mail store resides.