I actually setup something similar years ago with a gmail add-on. Was pretty intuitive and liked it. It would be advantageous to add additional features over this such as:

1. Adding points or estimated workloads to emails.

2. Adding notes to emails

3. Snooze emails (which would drop their priority on the board, but stay in the same lane until post snooze).

4. Highlight who is in the discussion thread.

5. Rules for lanes of work (for instance potentially emails from boss should go straight to “in progress”)