Of course the sneaky way to try and do this is actually by simply ask people how they like the newsletter and in case they feel it is useful.
You don't need to ly state these benefits. Design tools are understand part of email marketing communications. http://Potocki.org/__media__/js/netsoltrademark.php?d=launchhappy.co%2Fguides%2Fsquarespace-email-campaign-pricing-features-explained