The e-mails were sent to club members via the RFU's Game Management System (GMS).
If you haven't received the e-mail, make sure you have renewed your club membership for season 2026-27. You may also need to check your settings on GMS. There is a link to GMS at the bottom of the England Rugby website title page.
You can pay your membership via GMS or you can pay at the clubhouse bar - just ask for the rugby club card machine and specify what your payment is for.