O365 - Application Impersonation not working Tenant wide

Question

We have Application Impersonation turned on for about 4-5 service accounts, and it's not working for any of them. We can't "send as", we can't sync calendars, etc from any of our applications.

We have a ticket open with Microsoft, but it's been like pulling teeth to get someone on the phone. Does anyone have any idea's as to why this won't work?

Answer 1

Hi @JoFri ,

Did you receive any errors when the operation failed? Please ensure that you have correctly followed the steps introduced in the official document: Configure impersonation

I also found a related thread here: impersonate not working!
The issue was resolved by rerunning the commands again. You could try re-configuring it and verify the result again.

Step 1
New-ManagementScope -Name UserAdminScope -RecipientRestrictionFilter {RecipientType -eq "UserMailbox"}

Step 2
New-ManagementRoleAssignment –Name "UserAdmin" –Role ApplicationImpersonation –User UserAdmin -CustomRecipientWriteScope UserAdminScope

Step 3
Get-ExchangeServer | Where {$_.ServerRole -match "ClientAccess"} | Add-ADPermission -User "UserAdmin" -ExtendedRights ms-Exch-EPI-Impersonation -InheritanceType None
Get-MailboxDatabase | Add-ADPermission -User "USerAdmin" -ExtendedRights ms-Exch-EPI-May-Impersonate -InheritanceType All

---

If an Answer is helpful, please click "Accept Answer" and upvote it.

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.