Specifications

1.
2.
3.
4.
Assign the service account permissions to the Mailbox Databases on your Exchange server.
Open the Exchange Management Shell, and run the following command replacing with the Service Account <ServiceAccount>
username:
Get-ClientAccessServer | Add-AdPermission -User <ServiceAccount> -ExtendedRights
ms-Exch-EPI-Impersonation
Get-MailboxDatabase | Add-AdPermission -User <ServiceAccount> -ExtendedRights
ms-Exch-EPI-May-Impersonate
Depending on replication policies and Exchange Server activity, it may be helpful to perform a group policy update on the Exchange
Server to help replicate permissions. To do so, run the following command from the command line:
gpupdate /force