how to delete duplicates in outlook contacts

In the main body of the script, we simply run the RunQueryandEnumerateResults function to list all contacts in the mailbox. Then there is one more function specific to this script, DeleteContact which takes in parameters for the Contact object ID, The users UPN and the Access Token and removes a contact. RunQueryAndEnumerateResults – This function runs a Graph query and enumerates through result pages to return a combined result.GetGraphToken – This function takes in the details of an App Reg and Secret to request an Access Token.It uses two reusable functions that I use in a lot of my scripts which are: The script itself is pretty straightforward. I’ve detailed setting up an App Reg in the past so I won’t go through it all here but you’ll need to assign Application permissions and gather the Client ID and create a Client Secret to use in the above parameters.

The other thing you’ll need is an App Registration.

Mailbox – The User Principal Name of the target user.ClientSecret – A Client Secret from the Application Registration.TenantID – The Tenant (Directory) ID of the Azure AD tenancy.ClientID – The Client ID of an Application Registration.The script itself is pretty straight forward, it takes the following input parameters:

Of course the best way to prevent this is by running a single sync of contacts (and calendars) but still, due to sync failures or any number of other reasons, we can end up in this scenario. This scenario is pretty common when using any type of “Synchronization” type migration tool as contacts can often change in very small ways over time and tend to be duplicated in the destination. The first script that I wanted to share is a simple but effective Graph API / PowerShell based script to remove duplicated contacts in a users mailbox. I’ve decided that rather than store them locally where they tend to get lost to time, I’ll start a series of post here where I can share them with the community. I’ve recently completed a tenant to tenant consolidation and usually at the tail end of these types of projects, I end up with a library of scripts for different postfixes or modifications that I use to patch up things after migration.

How to delete duplicates in outlook contacts