My Diocese, the Diocese of Chicago, publishes the names and addresses of all the parishes in the Diocese on their web site. I bet your diocese does, too. That wouldn't reach all the members, but if you sent out letters to those addresses addressed to "Rector", "Senior Warden", "Junior Warden", "Treasurer", "Secretary", "Organist", etc., you'd probably hit someone who'd bring it to the attention of the rest of the parish.
That's a good thought.