G Suite Sync with Microsoft Outlook and RMS

Today I had the opportunity to try out sending RMS protected messages to external recipients who use native Exchange-Outlook and G Suite Sync with Outlook.

I send a message to the external recipients from Outlook.

The external recipient with Outlook (I’ll call her Carmen) already has AIP client installed and RMS enabled in her tenant. The message opens with no issues.

The external recipient with G Suite Sync and Outlook (I’ll call him Ben) receives the message with the following text in the reading pane.

This message with restricted permission cannot be viewed in the reading pane until you verify your credentials. Open the item to read its contents and verify your credentials.

After double clicking on the message, the message below is displayed. Note that the sender is MOD Administrator from the sender tenant.


After the Ben verifies his credentials, the email message is displayed.

So far so good.

Carmen replies all from Outlook; all is normal.

Ben replies all from his Outlook client; the original sender (MOD Administrator) and Carmen see this:


However, when Ben replies all from Gmail via the Web browser, he sees the following message:

“You’ll automatically get an email copy of this message.” along with the label and the owner of the messages.

The original sender (MOD Administrator) and Carmen can view the message with no issues.

Ben, however, sees that the message comes from Office365@messaging.microsoft.com, not from his email address.


After the Ben verifies his credentials, the email message is displayed.

In summary – if you are using G Suite Sync with Outlook and responding to an encrypted message, be aware that your recipients may not be able to view your responses.

Thanks for reading!