A board email address is a custom SendBoard email address that gets assigned to your Trello board when the Email for Trello Power-Up is set up on your board. This address is used to send and receive emails to and from your board.
Each Trello board that the Email for Trello Power-Up has been added to and set-up on, will have its own, unique board address.
You can change your board email address by editing the SendBoard Power-Up Settings, which you can access through the Trello sidebar as shown below:
Many teams prefer to send and receive emails using their own email address, without the
.sendboard.com part (e.g. email@example.com). You can do this by linking your existing email address to SendBoard and setting up forwarding rules. Have a look at this article for detailed steps on how to set up your custom email address: Custom email addresses