Office Outlook 2007 has an advanced architecture for handling conflicts in Cached Exchange Mode. There are a number of scenarios where users are prompted and user interaction is required. For example, one scenario is when two different third-party vendors update the same item, independent of each other. The user will get an error with the conflict information in the status bar. At that time, there could be a potential data loss as a result of one of the items taking precedence over the other one. Office Outlook 2007 and Exchange 2007 cannot "merge" conflicting items so one item might be moved to the Conflicts folder.

Conflict handling steps apply to both Office Outlook 2003 Service Pack 3 and Office Outlook 2007 Service Pack 1 working with either Exchange Server 2003 Service Pack 2 or Microsoft Exchange Server 2007 Service Pack 1 — when the Office Outlook 2007 or the Office Outlook 2003 client is configured to work in Cached Exchange Mode.

Any modifications that are done in an item when working Offline, or changes that are done in the timeslot when Outlook is waiting to synchronize items, forces the item to go through the synchronization process.

For more information about synchronization in Cached Exchange Mode, see Microsoft Knowledge Base article 870926: Description of Outlook 2003 with Cached Exchange Mode in an Exchange Server 2003 environment (http://go.microsoft.com/fwlink/?LinkId=124980).

Simplified Steps

• Step 1

  Outlook starts to synchronize and receive the hierarchy information from the mailbox - for example confirmation that the Conflicts folder exists.

• Step 2

  When there is a new Outlook Appointment item, it is tracked for potential duplication detection. This prevents both the possibility of two meetings in the Calendar, or a duplicate feed entry for RSS showing up online.

• Step 3

  If it is an existing Outlook item, did the same item change on the server?

  No, then we upload the item to the Exchange Server computer.

  Yes, the item did change on the Exchange Server computer. Then, the next step is the "Conflict Resolver" stage.

• Step 4

  The "Conflict Resolver" stage is where Outlook checks each modified property in the Offline Folder (OST) file to determine if any of the properties can run through an automatic resolution algorithm. The set of properties that can be automatically resolved are fairly small in number. If there are any properties that cannot be automatically resolved, the item that was changed last will become the winning item, including its complete property set. The losing item will be stored in the Conflicts folder and linked to the winning item.

  Is there a resolution rule that can automatically handle any of the OST changed properties?

  Yes, then we apply the rule for it and skip generating a conflict item.

  No, there is not an automatic way of correcting this, go into "Critical Conflict." At this stage, we keep the newest item (the one that was modified last) and move the entire older item into the Conflicts folder and close the check for this item.

  Note:
  The item located on the client or server, which has the latest modification time stamped to the item, will be available in the Inbox (or its subfolder) and the "old" version will be moved to the Conflicts folder.

• Step 5

  Download Exchange Server Outlook items.

• Step 6

  The synchronizing cycle is complete.

Scenario 1

A new item arrives in the mailbox on the Exchange Server computer. The item does not exist in the cache on the client computer. No conflict.

Scenario 2

A new item is in the cache on the client computer, and does not exist on the Exchange Server computer. No conflict.

Scenario 3

An item exists on both the client and the Exchange Server computer. The item is changed on the client. No conflict.

Scenario 4

An item exists on both the client and the Exchange Server computer. The item is changed in the mailbox on the Exchange Server computer. No conflict.

Scenario 5

An item exists on both the client and the Exchange Server computer. The item has changed the level of importance both on the client and in the mailbox on the Exchange Server computer. A conflict occurs.

Scenario 6

An item exists on both the client and the Exchange Server computer. The item has changed the subject both on the client and in the mailbox on the Exchange Server computer. A conflict occurs.

Scenario 7

An item exists on both the client and the Exchange Server computer. The item is changed by a third-party vendor both on the client and in the mailbox on the Exchange Server computer. The result will be a conflict.