Bananatag - Find out what happens to your emails after you press send! Add email tracking, attachment tracking, email scheduling and templates to your daily emails.
Out of Office Email Generator - Personalized, witty OOO replies for guilt-free vacationing.
GetNotify - GetNotify is a free email tracking software solution.
Rebump - Automatic follow up emails. Keeps on bumping until you get a reply.
Mailtrack.io - The best email tracking solution I've found. Free
Cop-Out - The ultimate excuse generator