Exchange 2007 keeps logging error: exceeded the maximum of 500 objects of type "objtFolder".

I think I saw a similar issue with this on my exchange server. In my case it was due to the users having some third party addin for outlook. In my case it was the linkedin toolbar. I would suggest checking to see if the user has anything like that added.

no 3rd party plugins etc., users dont have many folders or too many emails.

Any other suggestions?

To use Registry Editor to adjust the maximum number of open objects that a MAPI client can use at the same time

Start Registry Editor (regedit).

Step 1 Locate the following registry subkey: HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

Step 2 Right-click ParametersSystem, point to New, and then click Key.

Step 3 Type MaxObjsPerMapiSession, and then press ENTER to name the new subkey.

Step 4 Right-click MaxObjsPerMapiSession, click New, and then click DWORD Value.

Step 5 Type the object type, and then press ENTER to name the entry. For example, type objtMessage, and then press ENTER to create an entry that changes the default maximum of objtMessage objects.

Step 6 Right-click the entry that you created in Step 6, and then click Modify.

In the Value data box, type the new maximum number of objects to which you want to limit this entry, and then click OK.

Note : The server will automatically recognize the new limit within five minutes.

Please help me understand, what kind of objects are limited to 500 ?

Can we set to something crazy high, like 9999?

Thanks,

Whenever a use opens a message using Outlook (in online more) or OWA, the server keeps a message object in memory. The same happens for folders. The object for folders on the server is called objtFolder. The server has limits in place to prevent any one user from opening lots of objects on the server and using up all available memory, which would make the server stop working for all users.

Generally, most users have a small number of objects open unless they are trying to be malicious (very rare since this is not an easy way to be malicious) or more likely that they have a buggy add-in or client (such as a phone) that opens many objects. The best approach is to find the bad add-in/client and remove it. You can increase the limit, but that reduces security and it may not work. If one client can open 500 folders in a relatively short period of time, it might just open 9999 as well.

I have created key: MaxObjsPerMapiSession with objMessage with value of 1000

And I still get some errors some mailboxes:  

Mapi session "/O=ExchangeORG/OU=OU/cn=Recipients/cn=USER" exceeded the maximum of 500 objects of type "objtFolder".

Any other suggestions?

Thank you!