Was there a message along with the attachment? Some of us in my congregation also got a message, over a year ago, similar to what you're describing with CofC attached to it.
The elders were all over this and it was the talk of the car-groups for a few weeks last year.
It was almost like if you didn't get one you kinda felt bad and knew you weren't in somebody's contact list who shared a message with a hundred JW buddies email addresses in the To: field and you weren't included.