New type of Read receipt

Hello,

today I received this sort of read receipt notification. Instead of a name od the Receiver the notification only says: Someone opened.

Anyone any idea why?
Screenshot 2022-09-12 at 09.03.43

Greetings!
Did anyone reply to this inquiry regarding that message “SOMEONE OPENED” instead of the actual email address? I am also receiving this exact same message. Sometimes the tracker will give the exact email address of who opened my email but other times the status will say “OPENED BY: SOMEONE” and the time. This can get very confusing if there are multiple folks on an eblast.
Help!

Did you find the answer? I know my emails are being forwarded by the recipient without my consent. How can I gather evidence for that?