lms/community/templates/emails/mentor_request_status_update_email.html

<div>
  <p>Dear {{ member_name }},</p>
  <br>
  <p>Your request to join us as a mentor for the course {{ course }} has been {{ status }}.</p>
  <br>
  <p>Thanks and Regards,</p>
  <p>Team Community.</p>
</div>