Hello all, On an Server 2003 (SP1) machine with Exchange 2003 (SP2) i get the following error: Event Type: Error Event Source: MSExchangeIS Event Category: General Event ID: 9671 Date: 2-3-2006 Time: 5:01:57 User: N/A Computer: DC-VERTON Description: User SYSTEM has exceeded the allowed maximum number of simultaneous registrations for MAPI notifications. The configured maximum number of event notification registrations is 8. For more information, click http://www.microsoft.com/contentredirect.asp. Data: 0000: 31 00 30 00 2e 00 32 00 1.0...2. 0008: 30 00 30 00 2e 00 31 00 0.0...1. 0010: 34 00 2e 00 31 00 00 00 4...1... Can anyone tell me what I should do? I followed the link and it says: The administrator can set the maximum number of registrations and the context size setting by adding the following REG_DWORD values to HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem: Maximum Allowed Client Context Size (default is 16 bytes). Maximum Allowed Notification Registrations Per Client (default is 8). But these values are not present. Thanks in Advance. Mark