Quickly responding to someone interested in your listing is a best practice for increasing your chances of selling it. When you receive a message from someone interested in your listing, you'll be notified of email and also receive a text message if you've elected to be notified via text.
In the email you received, simply click the "reply" button in the email. This will take you to the message on The Tiny House Listings site. From there you can respond to the person's questions and also see a thread of previous communication with that person. You can also access your messages in box by clicking here.