I had received the passport copies request in Vancouver from a similar email address
DNCITVANTESTS@cic.gc.ca. Same had happened with my wife and we both responded to same email 6 weeks ago. Our status in ecas converted to DM 3 weeks ago. So, it's weird that you are told to re-send to a different email. anyways, it's a step on the way. I had lost 3 weeks earlier because my physical presence status had been completed and then had flipped back to +in progress". A week later I received the passport request.
So, make sure that you received an auto response from the received email.
Please don't be upset from such things. You are not far away from being a Canadian citizen. Good luck.