Mixmax Calendar - The fastest way to schedule meetings with anyone, anywhere
HTMLEmail.io - Responsive HTML email templates for startups & developers
Meetingbird for Gmail - View your calendar and schedule meetings right from Gmail
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Calendly - Say goodbye to phone and email tag for finding the perfect meeting time with Calendly. It's 100% free, super easy to use and you'll love our customer service.
MJML - The open source framework for responsive emails