app/views/mailboxer/notification_mailer/new_notification_email.html.erb
<!DOCTYPE html>
<div style="padding: 16px; background: white; text-align: left;">
<%= raw @notification.body %>
<hr>
<p style="font-size: 12px;">Make sense with Metamaps</p>
<%= render partial: 'shared/mailer_unsubscribe_link' %>
</div>