Cardbox can automatically create cards when you get an email, or you can attach individual emails to existing cards.
When you get a reply, Cardbox moves the card to the top of its list, so you can track who needs a response. All board members can reply, to share the workload.
Cardbox is free for small teams and personal use. If you plan to use Cardbox on more than 20 boards, please reach out so I can provision additional capacity. To get Cardbox, add the "Gmail by Cardbox" power-up to your Trello board.
Reach out if you have any questions, or feature suggestions! You can expect a reply in under 24 hrs.