Hybrid Exchange Email moderation issue

Issue with Group Moderation: Moderator who is on office 365(Exchange Online) is not getting approve or reject button when any user send email to all users for approval

When someone sends email to a moderated group, and the moderator is hosted on Office 365, the buttons for Approve and Reject are not showing at his email client.

We will talk about how important is to configure Remote Domains both in the on-premises Exchange environment and on Exchange Online to preserve headers and TNEF format between the two organizations. The TNEF format is what makes the Approve or Reject buttons appear in the email messages.

Reason

It turned out that a setting called TNEF (Transport Neutral Encapsulation Format) is causing this to happen. We need to make sure TNEF format is enabled when sending emails out to Office 365 tenant

Solution

We need to make our on-premise Exchange servers deals with both @contoso.mail.onmicrosoft.com and @contoso.onmicrosoft.com as a well behaved remote domains.

So create remote domain for @contoso.onmicrosoft.com and @contoso.mail.onmicrosoft.com at the on-premises Exchange server if none is already created by Exchange hybrid wizard.

 

Check if it is already created with below cmdlets.

Get-RemoteDomain

and then configure the TNEF to true simply by running

Set-RemoteDomain  with -TNEFEnabled $true

Same applies to Exchange Online, we need to create remote domain for @contoso.com with TNEFEnabled $true.