I have 3 requests to make your calendar feature much more dynamic and useful:
1. Please add a drag/drop reschedule feature for the calendar. Unschedule/schedule requires way too many steps.
2. Allow users the option to look at the calendar by day, week or month.
3. Please display the send times on the calendar so users can double check that they're not sending emails back-to-back, at the same time, etc. This would help with email fatigue that my clients experience with so many eblasts.