Exchange 2000 and Exchange 2003 mailbox size limits are not enforced in a reasonable period of time

Microsoft Exchange 2000 Server and Microsoft Exchange Server 2003 mailbox size limits may not be enforced in a reasonable period of time. If users log off and log on, performance does not improve. If you restart the information store, the limits take effect immediately.

The fix for this problem is included in the following:

• Microsoft Exchange Server 2003
• Microsoft Exchange 2000 Server Service Pack 4 (SP4)

To enable the fix, you must add the Reread Logon Quotas Interval value to the registry.

To add the Reread Logon Quotas Interval value, follow these steps:

1. Click Start, click Run, type regedit, and then click OK.
2. Locate and then click to select the following registry key:
   HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
3. After you select the key that is specified in step 2, point to New on the Edit menu, and then click DWORD Value.
4. Type Reread Logon Quotas Interval, and then press ENTER.
5. Right-click Reread Logon Quotas Interval, and then click Modify.
6. In the Value data box, type the reread logon quotas interval in seconds, and then click OK.
   
   Note The default value is two hours (7200). The recommended value is 20 minutes (1200).
7. On the File menu, click Exit to exit Registry Editor.

Because the Reread Logon Quotas Interval value depends on the DSAccess cache and the mailbox information cache, the exact time before the changes take effect also depends on the DSAccess cache refresh time and the mailbox information cache refresh time. The default caching mechanism of DSAccess is 10 minutes. The default caching mechanism for the mailbox information cache is two hours.

You can edit the registry to change the DSAccess cache and the mailbox information cache refresh time to less time. However, this change affects performance because DSAccess performs more Active Directory lookups.

To control the DSAccess cache, change the CacheTTLUser registry value: To control rereading the logon quotas in the mailbox information cache, change the Mailbox Cache Age Limit value: You must restart the information store after you make any of these registry changes. Also, if you set the time-out values to very low values, you may affect the performance of the server.