Recipients of encrypted messages who receive encrypted or rights-protected mail sent to their, Gmail, and Yahoo accounts receive a wrapper mail that directs them to the OME Portal where they can easily authenticate using a Microsoft account, Gmail, or Yahoo credentials.Įnd-users that read encrypted or rights-protected mail on clients other than Outlook also use the OME portal to view encrypted and rights-protected messages that they receive.' Supported Outlook clients include Outlook desktop, Outlook Mac, Outlook mobile on iOS and Android, and Outlook on the web (formerly known as Outlook Web App).' 'All Microsoft 365 end-users that use Outlook clients to read mail receive native, first-class reading experiences for encrypted and rights-protected mail even if they're not in the same organization as the sender.

If you don't want to update your AIP settings or migrate to the unified labeling experience you could at least configure OME (for the end-users to choose as an option or as mail flow rule) as it should solve the particular external encryption issue. Not only in Office Message Encryption but you mentioned AIP as well. There's really no need to look for third-party solutions when you have them built-in with your subscriptions.

Microsoft secure email powershell