Greetings, I am running a mixed 2007 2003 environment. In one of the 2007 offices, i am having an issue where users send calendar requests but exchange looses them. In the event log i find the following. Event ID: 1014 Source: MSExchange Store Driver The store driver failed to open the message item for event 13017406 mailbox db5cd0c6-88ef-4533-bc1b-1e3283af97b1 MDB 44698a03- b3a1-460e-8bd9-de2c79be17eb. An NDR won't be generated. Everything else works fine. This is isolated to one E2K7 server out of 21. Following the MS guidance about this particular error suggests using message tracking, however message tracking does not even see the message. Thanks in advance for any help. K

How many mailboxes are affected? Can you move them to another store?

Hi Kevin, Do you have any Quest software on it? Please make sure Quest service is not running or is not integrated with Exchange.Best Regards!

Hi Kevin, We had a similar issue in our environment and found that root casue can be multiple sources. One of them being user error. I guess some of the affected users have mobile devices and/or using Outlook delegates? Important to consider: - Outlook delegate and owner must use the same version of Outlook (also same patch level / check build number) - check delegate config in Outlook (meeting request should only go to one delegate and a copy to the owner) - update mobile device OS to lates version Hope that helps Description of common scenarios in which Calendar information may be removed from the Calendar or may be inaccurate http://support.microsoft.com/kb/899704/ Working with support to troubleshoot the Outlook calendar in an Exchange environment http://technet.microsoft.com/en-us/library/cc891495(office.12).aspx Current issues with Microsoft Exchange ActiveSync and Third Party Devices http://support.microsoft.com/kb/2563324 How to troubleshoot missing and duplicate appointments in Outlook http://support.microsoft.com/kb/2563324 Considerations when you use the Delegate Access feature in Microsoft Outlook http://support.microsoft.com/kb/829217