Outlook 2010 Sync Issues Folder is full of sync logs (“Synchronization Log:” and “Modification Resolution”) with Exchange 2010 Mailbox

After I moved my mailbox to Exchange 2010, I started seeing two kinds of Sync logs in “Sync Issues” folder: “Synchronization Log:”  and “Modification Resolution”.

Whenever I delete something and empty my “Deleted Items” folder, I see a sync log in a minute. It says,

22:45:33 Uploading to server 'CAS1.company.com'
22:45:33 Synchronization of some deletions failed.
22:45:33          [0-130]
22:45:34        1 view(s)/form(s) updated in online folder
22:45:34        4 view(s)/form(s) deleted in online folder

For the record, it doesn’t happen if my Outlook is on ONLINE mode. It only happens in Outlook Cached Mode.

It drove my users crazy. It seems it drives lots of people crazy as I read in technet forums. So far no one finds solution for this. There are many explanations why it happens, but no solution. Exchange 2010 SP1 doesn’t fix this issue either. Well, I have been told it’s Outlook 2010 related issue, not an server problem.

I called Microsoft support and they confirmed they themselves are getting this logs. If you find an solution, please reply to this blog. Or hopefully next Office 2010 service pack fix this one.

 

Whenever I did something with Calendar items (deletion or modification), I see “Modification Resolution” log in Sync Issues folder.

14:30:00 Message class: {SU:IPM.Appointment}
14:30:00 Appointment Conflict Resolution
14:30:00 Local subject: {SU:Team Lunch - Placeholder}
14:30:00 Remote subject: {SU:Team Lunch - Placeholder}
14:30:00 Local Message Entry ID: {CB:70, LPB:0x00000000D7754433D4F990489C0A23AA08ED28C307005EF0C574BA12B14F805532F0BB58596200000A794FE70000FE23979F836CCA43B84FC495B894A5110000003B56A30000
...
...
14:30:00 Not equal (conflict) named property: 0x00150003
14:30:00 Conflict Merge named property: 0x00150003
14:30:00 Critical properties merged into remote item.
14:30:00 Successfully auto-resolved

I heard BES server also generates these logs consistently.  I came to know how to stop “Modification Resolution” logs. Modification Resolution log explains what Outlook did on a conflict on items. To stop generating this log, create a registry entry as below with option 0.

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.>