Dear Christina
Thank you for posting in Microsoft Community.
I understand you have an issue with opening encrypted mail. Before moving forward, we need more detailed information about the situation you are experiencing.
- What client are you using to try and open the mail?
- May we confirm how the mail was encrypted? (Transport rules or Using Outlook)
Looking forward to your response.
Sincerely,
Momo Kamboni | Microsoft Community Moderator