We recently started using Exchange Hosted Encryption with Exchange Online. It works great for sending messages to external users. Our encryption and decryption rules are working as expected.
In our business, we need to send an encrypted message to an external user, and carbon copy internal user(s). Because of the way the encryption process works, the external message is fine, but the internal message comes back not readable.
The internal user receives a secure message (as if they are external), instructing to open the attachment (message_zdm.html) to view the message. After opening the attachment, and logging into the portal there is only a winmail.dat attachment present. Even with a viewer that can open .dat files, any attachments to the original message are missing.
I understand we could send each message twice. The external message with encryption, and the internal message without, but I am looking for other options. Has anyone else experienced this, or have any suggestions? Thanks.