User Quotas

You can specify user quotas by disk space or by number of messages. Disk space quotas specify, in bytes, the amount of disk space for each user. Disk quotas apply to the total size of all the user’s messages, regardless of how many mail folders the user has or the total number of user messages. Message quotas allow you to limit the number of messages stored in a user’s mailbox.

Quota information is stored in user LDAP attributes (Table 18–6) and configutil variables (Table 18–7). (See the Sun Java System Communications Services 6 2005Q4 Schema Reference for latest and complete information.) In addition to setting the quota itself, Messaging Server allows you to control the following features:

• Quota notification sends users a warning message when they have reached a disk quota threshold.

• Quota enforcement halts delivery of messages into the message store once the quota is exceeded, or it allows message delivery even if the quota is exceeded.

  If message delivery is halted due to over quota, incoming messages remain in the MTA queue until one of the following occurs:

  • The size or number of the user’s messages no longer exceeds the quota, at which time the MTA delivers the messages.

  • The undelivered message remains in the MTA queue longer than the specified grace period, at which time messages are returned to sender. (See To Set a Grace Period).

    Disk space becomes available when a user deletes and expunges messages or when the server deletes messages according to the aging policies you have established.

• Quota Default sets default quotas for all users or different quotas for specific users. To determine if a user is over quota, Messaging Server first checks to see if a quota has been set for the individual user. If no quota has been set, Messaging Server looks at the default quota set for all users.