Topic Last Modified: 2007-09-20

This topic provides information about why the mailbox size limits do not take effect immediately after a configuration change.

After you configure the mailbox size restriction for a mailbox, that mailbox user can continue to send and receive messages that cause the mailbox to exceed the configured mailbox size. The configured limits are enforced after a period of time, but do not take effect immediately. Restarting the Microsoft Exchange Information Store service causes the configured limits to take effect immediately.

Resolution

This issue occurs because the Microsoft Exchange Information Store service uses the cached mailbox configuration to enforce mailbox size limits. The configuration change does not take effect until the cache is refreshed. The default interval for refreshing the cached mailbox information is two hours.

To resolve this problem, you can change the refresh interval for the mailbox information cache by modifying the Reread Logon Quotas Interval value in the registry for the Microsoft Exchange Information Store service. The Reread Logon Quotas Interval value depends on the Directory Service Access (DSAccess) cache and the mailbox information cache. Therefore, you must configure the CacheTTLUser and Mailbox Cache Age Limit values as well.

Incorrectly editing the registry can cause serious problems that may require you to reinstall your operating system. Problems resulting from editing the registry incorrectly may not be able to be resolved. Before editing the registry, back up any valuable data. 

Important:
If you set the cache refresh intervals to very low values, you may affect the performance of your Exchange server. We recommend a value of 20 minutes for refreshing the mailbox information. 

Before You Begin

To perform this procedure, the account you use must be delegated the following:

  • Exchange Server Administrator role and local Administrators group for the target server

For more information about permissions, delegating roles, and the rights that are required to administer Microsoft Exchange Server 2007, see Permission Considerations.

Procedure

To use the registry editor to configure the mailbox information cache refresh interval for the Microsoft Exchange Information Store service

  1. Start the registry editor and connect to the registry of the server for which you want to configure the Microsoft Exchange Information Store service.

  2. Locate the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem key.

  3. To configure the interval for refreshing the information for mailbox size limits, do the following:

    1. Right-click ParametersSystem, select New, and then select DWORD value.

    2. Name the new DWORD value Reread Logon Quotas Interval.

    3. Right-click Reread Logon Quotas Interval, and then click Modify.

    4. For the Base option, click Decimal.

    5. In the Value data text box, enter a positive integer specifying the mailbox information cache refresh interval in seconds, and then click OK. The default value is two hours (7200 seconds). The recommended value is 20 minutes (1200 seconds).

  4. To change the mailbox information cache age limit value, do the following:

    1. Right-click ParametersSystem, select New, and then select DWORD value.

    2. Name the new DWORD value Mailbox Cache Age Limit.

    3. Right-click Mailbox Cache Age Limit, and then click Modify.

    4. For the Base option, click Decimal.

    5. In the Value data text box, enter a positive integer specifying the mailbox information cache age limit in minutes, and then click OK. The default value is two hours (120 minutes).

  5. Locate the HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchange ADAccess\Instance0 key. If this registry key is not present, create it using the following steps:

    1. Right-click MSExchange ADAccess, select New, and then select Key.

    2. Name the new key Instance0.

  6. To configure the DSAccess cache refresh rate, do the following:

    1. Right-click Instance0, select New, and then select DWORD value.

    2. Name the new DWORD value CacheTTLUser.

    3. Right-click CacheTTLUser, and then click Modify.

    4. For the Base option, click Decimal.

    5. In the Value Data text box, enter a positive integer specifying the cache expiration interval for the user data object in seconds. The default value is 5 minutes (300 seconds).

      Important:
      Lowering this value affects performance because the Exchange Server will perform more Active Directory directory service lookups.

  7. Close the registry editor.

  8. Restart the Microsoft Exchange Information Store service.

For More Information

For more information about managing message size restrictions in Exchange 2007, see Managing Message Size Limits.