Sun Java System Messaging Server 6 2005Q4 Administration Guide

About Message Store Quotas

A message store quota is a way of setting a limit or quota for how much disk space or how many messages can be used by users or domains. This section contains information about the following:

For further information, see To Monitor Quota Limits

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.

Domain Quotas

As for users, quotas can also be set for domains by either number of bytes or number of messages. This quota is for all the cumulative bytes or messages of all the users in a particular domain.

Exceptions for Telephony Application Servers

To support unified messaging requirements, Messaging Server provides the ability to override quota limitations imposed by the message store. This guarantees the delivery of messages that have been accepted by certain agents, namely telephony application servers (TAS). Messages accepted by a TAS can be routed through a special MTA channel that ensures the message is delivered to the store regardless of quota limits. For more information about configuring the TAS channel, see Chapter 12, Configuring Channel Definitions.

Message Store Quota Attributes and Parameters

This section contains the message store quota attributes and parameters. For detailed information on these attributes and parameters, refer to the Sun Java System Communications Services 6 2005Q4 Schema Reference.

Table 18–6 Message Store Quota Attributes


Attribute	Description
mailQuota	Bytes of disk space allowed for the user’s mailbox. Special values: 0 - No space allowed for user’s mailbox. –1 - No limit on space usage allowed. -2 - Use system default quota. (`configutil`parameter `store.defaultmailboxquota`)
mailMsgQuota	Maximum number of messages permitted for a user. This is a cumulative count for all folders in the store. Special values: 0 - No message allowed for user’s mailbox. -1 - No limit on number of messages allowed. -2 - Use system default quota. `(configutil` parameter `store.defaultmessage.quota`.)
mailUserStatus	Status of the mail user. Can be one of the following values: `active` - mail is processed as normal. Default is active. `inactive` - user’s mail account is inactive. A transient failure is returned. `deleted` - Account marked deleted and ready for purge. Permanent failure returned. Access to mailbox blocked. `hold` - Mail sent to the hold queue and access to the mailbox is disallowed `overquota` - The MTA will not deliver mail to a mailbox with this status. This is the status set when the `configutil` parameter, `store.overquotastatus` is on.
mailDomainDiskQuota	Bytes of disk space allowed for the cumulative count of all the mailboxes in a domain. A value of -1 means no limit on space usage. (Default) To enforce the domain disk quota run the command: `imquotacheck -f -d` `domain`
mailDomainMsgQuota	Maximum number of messages permitted for a domain, that is, the total count for all mailboxes in the store. A value of -1 means no limit. (Default). To enforce the domain message quota run the command: `imquotacheck -f -d` `domain`
mailDomainStatus	Status of the mail domain. Values and default are the same as `mailUserStatus`.

Table 18–7 Message Store configutil parameters


Parameter	Description
store.quotaenforcement	Enable quota enforcement When off, the quota database is still updated, but messages are always delivered. Default: On
store.quotanotification	Enable quota notification. Default: On
store.defaultmailboxquota	Store default quota by number of bytes. Default: -1 (unlimited)
store.defaultmessagequota	Store default quota by number of messages. Numeric. Default: -1 (unlimited)
store.quotaexceededmsg	Quota warning message. If none, notification is not sent. Default: None.
store.quotaexceededmsginterval	Interval, in days, for sending overquota notification. Default: 7
store.quotagraceperiod	Time, in hours, a mailbox has been overquota before messages to the mailbox will bounce back to the sender. Number of hours. Default: 120
store.quotawarn	Quota warning threshold. Percentage of quota exceeded before clients are sent an over quota warning. Default: 90
local.store.quotaoverdraft	Used to provide compatibility with systems that migrated from the Netscape Messaging Server. When ON, allow delivery of one message that puts disk usage over quota. After the user is over quota, messages are deferred or bounced, the quota warning message is sent, and the quota grace period timer starts. (The default is that the quota warning messages are sent when the message store reaches the threshold.) Default: Off, but is treated as on if store.overquotastatus is set, otherwise the user can never go over quota and the `overquotastatus` is never used.
local.store.overquotastatus	Enable quota enforcement before messages are enqueued in the MTA. This prevents the MTA queues from filling up. When set, and a user is not yet over quota, but an incoming message pushes the user over quota, then the message is delivered, but the mailuserstatus LDAP attribute is set to overquota so no more messages will be accepted by the MTA. Default: off