The source agent may occasionally be seen to return an error similar to this:
"08/02/2012 12:19:22 MSAApp::ProcessMailbox Error -2147221233 Invalid mailbox '/o=ExchangeOrg/ou=Exchange Administrative Group (FYDIBOHF23SPDLT)/cn=Recipients/cn=user1'(Infostore GUID: '22FD111B17E3487A9E6E2C11EE4354CC')"
If Calendar sync is used before mail sync then CSA will log the folowing:
CMBMConn::GetMailboxInfo TraceMsg 4808 Retrieving mailbox information (Mailbox: 'LEDN', Infostore: '', MailboxGUID: '').
2/24/2014 4:18:42 PM CMBMAdmin::SyncMailboxInfoEx Error -2147221233 Cannot retrieve the mailbox information.
2/24/2014 4:18:42 PM CMBMAdmin::SyncMailboxInfoEx Error 20 Resume without error
This can sometimes occur if the source mailbox is empty and has never been opened with Outlook
Create an Outlook profile to open the mailbox. Then logon to the mailbox and send the user an email to themselves through Outlook. Then try processing the mailbox again with the source agent