I was getting many “Modification Resolution” “Appointment Conflict Resolution” emails in Outlook 2010. I found that the best way to deal with these logs is to disable them thus:
Key: HKEY_CURRENT_USER\ Software\Microsoft\Office\14.0\Outlook\Options
DWORD: EnableConflictLogging
Values:0 = Never save Modification Resolution logs
1 = Always save Modification Resolution logs
2 = Save Modification Resolution logs when a “critical conflict” occurs
<This is the new Default behavior when the EnableConflictLogging dword does not exist.>
Thanks to: http://anandthearchitect.wordpress.com/2010/10/09/outlook-2010-sync-issues-folder-is-full-of-sync-logs-synchronization-log-and-modification-resolution-with-exchange-2010-mailbox/#wpl-likebox