Dear, Since migrating to Windows 7 (64 bit) and Office 2010 (32 bit) we have the following issue, only appearing when users have access to a secondary mailbox which includes a lot of folders: The user gets the following error after a working a while: "Cannot expand the folder. Your server administrator has limited the number of items you can open simultaneously. Try closing messages you have opened or removing attachments and images from unsent messages you are composing." Server side, an error ID 9646 is generated with the following information: Mapi session "/o=<domain/user>" exceeded the maximum of 500 objects of type "objtFolder". Having noticed a lot of similar threads on this forum, I browsed them all but came to no satisfactory conclusion. - Chimney offloading is disabled (by default, apparently on server 2008) - KeepAliveTime is 5 minutes, not 2 hours - connection limit is 500 (not 32) - "Download shared folders" disabled Pretty much every solution I've seen that microsoft offers pertains either to 2003 SP1 server installations or to Outlook 2007 clients. We never ran into this issue when we used Outlook 2007 clients. The closest I have come to a description of the error was on this hotfix page: http://support.microsoft.com/kb/983316 Alas, this again pertains to Outlook 2007. Would the hotfix work for 2010 as well? Could anyone help me with this issue? Yours truly, Willem Goethals

Have you tried creating a hierarchy of folders so that there aren't a lot at any one level?Ed Crowley MVP "There are seldom good technological solutions to behavioral problems."

In outlook you can uncheck the checkbox that say "Download Shared Fodlers" and "Download Public Foldes favorites" it is located in the same configuration place where you set your exchange servername, open additional mailboxes. You can control this settings with Group Policy if you like. lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com

Hi Willem, We can also try increasing the limitation size for objtFolder by referring to the following article: http://technet.microsoft.com/en-us/library/aa996193(EXCHG.80).aspx Thanks, Simon

The limit is there for a reason. By increasing it you put more load on the server which might be perfectly OK. But be be carefull not to increase it like crazy. Have also seen from real life that increasing the limit most often dont solve the problem. Many times it is badly written applications fault and very often this setting in Outlook 2010 mentioned above. lasse at humandata dot se, http://anewmessagehasarrived.blogspot.com