Using iTunes to sync contacts on your legacy system and your migration to Exchange

oooohhhh boy.

You think using Apple iTunes on your legacy system (in this case Oracle Beehive) to sync contacts will result in no problems (because Apple has such high quality (yes, this is sarcasm) software in the Windows world.....).  But when you migrate into Exchange some contacts are duplicated.

But you migrate and you get some duplicate contacts.  Not from ALL users, just the ones using iTunes.

Yep.  That happened in a real world site this past weekend.

Use this procdure post-migration to de-dupe:

Delete duplicate contacts

If you imported contacts into Outlook by using the same names or e-mail addresses that already exist in your Contacts folder, and you selected the Allow duplicates to be created option in the Import and Export Wizard, you might have unwanted duplicates of several or all of the contacts that you imported.

Removing the unwanted duplicate contacts is a manual process, but the following is the easiest way to do it.

NOTE:  These instructions are for Outlook 2007. Instructions are also available forOutlook 2013 or Outlook 2010.

In Contacts, select the contacts folder that has duplicate contacts.

In the Navigation Pane, under Current View, click Phone List. This is the best view to scan your contacts list and see the duplicate contacts. Now you can sort the list by modified date and group the duplicates together.

On the View menu, point to Current View, and then click Customize Current View.

Click Fields, select Modified in the Available fields list, and then click Add.

Click Move Up until Modified is at the top of the Show these fields in this order list.

Click OK twice.

In the list of contacts, hold down CTRL while you select each duplicate contact.

When you have selected all the duplicate contacts, press DELETE.

This is from:

https://support.office.com/en-us/article/Resolve-or-delete-duplicate-contacts-0fa9c0a0-499a-48ab-b818-4e6463ccb9fa