MailPace - A Transactional Email Provider from the creators of idbloc.co - for apps, websites and anything else
HTMLEmail.io - Responsive HTML email templates for startups & developers
Swink - Short links with stats and automatically branded QR codes
Templates by Email Monster - Hundreds of free, responsive email templates. Pick and edit.
Urlnet - Dead simple anonymous url shortener
MJML - The open source framework for responsive emails