Trying to get iPhones working for one of our customers. SBS 2003 SP2, Exchange V6.5 SP2. OWA is working correctly. Verified all of the settings we normally need to modify in a SBS2003 Activesync scenario. Getting the following error from testexchangeconnectivity.c
An ActiveSync session is being attempted with the server.
Errors were encountered while testing the Exchange ActiveSync session.
Attempting to send the OPTIONS command to the server.
The OPTIONS response was successfully received and is valid.
Headers received: MicrosoftOfficeWebServer: 5.0_Pub
Public: OPTIONS, POST
Allow: OPTIONS, POST
Date: Fri, 11 Feb 2011 19:54:32 GMT
Attempting the FolderSync command on the Exchange ActiveSync session.
The FolderSync command completed successfully.
Number of folders: 11
Attempting the initial sync to the Inbox folder. This initial sync won't return any data.
The Sync command completed successfully.
Attempting to test the GetItemEstimate command for the Inbox folder.
ExRCA received an error in response to the GetItemEstimate command.
Exchange ActiveSync command GetItemEstimate failed with error code InvalidSyncKey.
My searches for InvalidSyncKey have not been been helpful.