Article ID: 2019948 - View products that this article applies to.
Outlook Dialogue box pop- up stating “Trying to Connect to Microsoft Exchange Server.” You may get a MAPI_E_LOGON_FAILED
Windows Server 2008 GC’s have a limitation of 50 concurrent NSPI connections per user.
Applications such as Outlook 2007, Blackberry Enterprise Server, or any application that will create multiple NSPI connections to a DC/GC can experience these symptoms.
Note: There is no specific upper-limit to this setting beyond the limits that are imposed by it being a DWORD (that is, 0xffffffff or about 4 billion). Configuring the server in this manner will make it function similarly to Windows Server 2003 in terms of the maximum number of NSPI connections that are allowed per user. This modification was made to Server 2008 to limit the ability of one user account depleting the resources of any particular DC. Modifying this entry may cause performance issues on the DC as we create a new page in memory for each NSPI connection.
For more information, see the following article from the Microsoft Knowledge Base online:
(http://go.microsoft.com/fwlink/?LinkId=151500)for other considerations.
Article ID: 2019948 - Last Review: February 26, 2010 - Revision: 1.0