Argh re the misplaced credit. Reminds me a great deal of doing Business Analysis work for a large insurance company. I worked for a VP who was notoriously late and last-minute about everything. But when it came to the work being pumped out (which I did, by the gallon, and it meant that I usually came in at 6 and stayed until 6, with no OT), he received every morsel of the credit.
This is why I don't work there any more, among other reasons.
But one of the reasons why I had no credit was because I was a behind-the-scenes person. That wasn't by choice; it was how the VP had made things.
You have the chance to not be behind the scenes. So to me that means what osso said - to no longer send private emails and just send out to the group and let them all see. It may seem silly, and overdoing it, but you're not getting recognized properly. This is a volunteer organization. That means that the only thing the boss can offer you is praise and recognition. You aren't getting that, or at least not enough of it, so you need to make it so that it's obvious that you should be getting praise and recognition.
