In my current project, I am using Quest Migration Manager tool to perform AD and EX migrations. I was getting the following error message in the Calendar Sync agent log file and Calendar synchronization wasn’t working:
CSession::Logon Error –2147221231 The information store could not be opened. - MAPI_E_LOGON_FAILED (MAPI 1.0) Low level error: 0x0 File: 'aeWrapHelpers.h' Line: '279'
According to the Quest documentation, it is due the firewall issue or the source and target Exchange servers cannot communicate over MAPI protocol. Anyway in our case it was due the NetBIOS name resolution. Once we corrected the name resolution issue, the Calendar Sync started working.