Later.io
6.6#18 in email scheduling softwareFrom $3.33 a yearFree planWeb
VisitLater.io suits people who want to schedule messages for themselves or others, or set recurring reminders for reports, habits, or payments. It may also fit co-workers coordinating reminders by email.
Mixmax suits revenue teams that work in Gmail or Outlook and want email sequences, tracking, scheduling and CRM activity in one workflow. It is not suited to users of Apple Mail, Yahoo or other email providers.