You use Policy Based Encryption and have received NDR messages from [email protected] to your mailbox with subject: Your email has not been delivered.
Encrypted Mail Gateway - Your Message Was Not Sent
Email Security.cloud
The encryption system could not process the message if there is no X-ContentInfo in the message header.
Please make sure that all messages coming from Email Security.cloud to be processed for encryption have the X-Contentinfo in the message header.