I'm testing the implementation of OME in our organization, and I have a question:
Sending a word/excel attachment in an encrypted email to a recipient with no Microsoft 365 subscription, results in recipient not able to open the file. The preview function in the browser for viewing the encrypted message is able to view the file, but downloading and trying to open/edit the file fails. Opening a excel file in XLS viewer or older local office version triggers RMS saying he doesn't have persmission to the document.
Is this by design, or am I doing something wrong? What are the requirements for sending OME encrypted office-file attachments to external recipients?