Don't send the same email plan to All your subscribers. Don't expect all your list react though but don't let up on sending out feedback emails either.
Here is a useful one of how many emails to send: A follow-up campaign should email people one email each and every for about two weeks. http://www.acewirespring.net/__media__/js/netsoltrademark.php?d=Launchhappy.co%2Fguides%2Fsquarespace-email-campaign-pricing-features-explained