Changes to primary Windows NT account on mailbox do not take effect

If the primary Windows NT account for a mailbox is changed, the new primary Windows NT account does not have immediate access to the mailbox and the previous primary Windows NT account still maintains access for some period of time.

This problem may also occur after a move mailbox operation.

The information store caches information contained in the directory store and, by default, it re-reads it every 120 minutes. Therefore, any change to a directory object (for example, a primary Windows NT account change) is not reflected in the information store for two hours.

Warning Serious problems might occur if you modify the registry incorrectly by using Registry Editor or by using another method. These problems might require that you reinstall your operating system. Microsoft cannot guarantee that these problems can be solved. Modify the registry at your own risk.

To have changes to directory objects picked up immediately by the information store, follow these steps:

1. Run Registry Editor (Regedt32.exe).
2. Locate the following key:
   HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem
3. On the Edit menu, click Add Value.
4. Enter Mailbox Cache Age Limit for the Value name.
5. Type REG_DWORD for the Data type.
6. Type 1 for the Data of type DECIMAL, and then click OK.
   
   NOTE: This registry entry is not a switch, it is a setting. If it is set to 1 the server rereads the cache every minute; if it is set to 2 the server rereads the cache every 2 minutes, and so forth.
7. Stop the information store service.
8. Restart the information store service.

The information store now updates its mailbox cache frequently by rereading the directory every minute.

In Microsoft Exchange Server 4.0 and 5.0, the information store rereads the directory every time there is a change to a directory object. This process was not optimized and did not offer the best performance. To optimize performance, Exchange Server 5.5 caches the directory information and rereads the directory every two hours by default.