DeleteItem Ignores ChangeKeys

According to our documentation, DeleteItem calls should fail with a ErrorStaleObject error when the ChangeKey is not the most recent one. This, however, is not the case. In Exchange 2007, the ChangeKey is completely ignored in DeleteItem calls. This decision was made on the logic that if you are trying to delete an item, chances are you don’t care if you have the most recent copy or not. But, what if you do?

You could try doing a GetItem, check the ChangeKey and then call DeleteItem right after, but that still leaves a small window of time between your GetItem and your DeleteItem calls where the item may have been changed.

Here’s a workaround which will help you implement the logic yourself using pull notifications.

1. Do a Subscribe on the folder of the item to subscribe for Pull notifications.
2. Next, do a GetItem and ensure that you do, in fact, have the most recent copy.
3. Do your DeleteItem.
4. Do your GetEvents to check for notifications.
5. If you get just a MovedEvent, then your item was deleted without having been modified (you get a MovedEvent because the item was moved to the Deleted Items folder). You may get a DeletedEvent depending on which flags you passed to DeleteItem. If you get a ModifiedEvent before your MovedEvent, you can then go retrieve the item from the Deleted Items folder and check the values of the properties from the item there. If you hard deleted the item (and therefore got a DeletedEvent) you cannot go get the latest copy from Deleted Items, because it isn’t there.
6. Unsubscribe.