I hate mailto - Stop websites from opening your email client.
MailtoUI.js - Enhance your mailto links with a convenient user interface.
Mailjoy - Delightfully easy direct mail marketing. A DIY direct mail tool created for marketing and growth teams. Design, mail & track personalized direct mail postcards and letters. Digital marketers use Mailjoy to send data-driven mail campaigns.
MailTime for Android - Blurring the line between messaging and emailing
The Simple Postcard - Text a photo to mail it as a postcard