You have a Microsoft Exchange Server 2019 organization.
You purchase a Microsoft 365 subscription and configure Active Directory synchronization.
You use a smart host for all email communication between the organization and the Internet. The smart host performs email hygiene and alerts message headers.
You plan to run the Hybrid Configuration wizard to create an Exchange hybrid deployment and change the MX record to point to Exchange Online.
You need to decommission the smart host from the organization.
What should you do first?