A content delivery system coupled to a computer network can provide large volumes of content to large numbers of recipients. The content is collected into digests and individual articles to be sent in email via an email channel established by the content delivery system to the recipients through the computer network. Content producers submit content for aggregation into various email deliveries and submit initial scheduling information. The scheduling information may specify target characteristics of preferred recipients of the content as well as general and initial scheduling preferences for email delivery. The content delivery system utilizes the initial scheduling information as a starting point for scheduling email deliveries. The system measures levels of content interaction by the recipients to gauge corresponding interest levels in the content. Using recipient interest levels as feedback, the content delivery system is able to modify and extend scheduling details to optimally schedule further deliveries of content.