Tagging External Emails

I’m trying to tag emails originating from, or including senders / recipients that are outside my organization.
This is a very useful option in Outlook and I thought I could just create a rule by specifying the “people” to [email protected]
But this didn’t work - is there any information on how I might achieve this?

cheers
Markus

It will look like this:

Ah! One click further then I looked :slight_smile:

Thank you very much!