Enable Hybrid Exchange Attributes In AD Connect

AD Connect Sync Exchange attributes

If you’re setting up a hybrid exchange environment with Office365 these are the steps required you need to change within your Azure AD Connect sync tool before you run the hybrid office365 wizard.  You need to make sure you have your onprem exchange AD attributes synced to exchange online.  These are the steps used i did for a client running Exchange 2016

Assumptions

1. AD Connect is already syncing with Azure AD
2. AD Connect was installed after you had Exchange installed and AD schemer extended as part of Exchange installation

Enable sync of exchange attributes to Exchange Online

As part of enabling hybrid exchange you will need to enable the synchronisation of the onprem exchange AD attributes to Office365

These are the steps to enable the sync of exchange attributes within AD Connect

Launch AD Connect tool and click configure

Click customise synchronising options

Enter a global Azure AD admin credentials

Leave these settings and click next (confirm your Active Directory Forest)

Leave these settings and click next

On this screen you want to select Exchange hybrid deployment, click next

Click configure

Now perform a full Import / Full synchronisation / Export to replicate the exchange attributes to Office365

Run the following powershell command to start this:

You should now see you’re onprem exchange mail enabled objects in Office365:

Login to your exchange online admin center – Select recipients / Contacts

They are represented as contacts in exchange online as below.  Once you migrate a mailbox to exchange online, it will then show up under mailboxes