There are many different types of notifications that you can receive from a Market appraisal. To access these, edit the recipients or simply turn them off, you need to go to Marketing and Autopilot >> Automations.
From here you can see all the automations that are in Lifesycle, the top 8 automations all relate to market appraisals.
To edit the user that recieves the notification emails, simply click the drop down list on the right and select the users you would like to be notified.
If you would like to select multiple users, then click select users, and then click the box with the pencil in it to select the users.
Too switch off the notifications, simply click the green toggle on the right of the notification so that it turns grey.