On your partner dash under Storefront > Support, please click the "+ add support link" button and enter in this email: firstname.lastname@example.org.
Change "yourmarketname" to the name of your site. For example: email@example.com
There is nothing else needed on your end -- you do not need to set up this email on your server.
*Please note: You can also put this as the "email from address" but for the email to appear on your storefront for customers to see, you need to click + add support link.