Lob - A simple API to integrate print & mail solutions into your applications.
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.
Stannp - Stannp helps to create and send postal Direct Mail campaigns: letters or postcards.
The Simple Postcard - Text a photo to mail it as a postcard
PostGrid - Transform your Offline Communications. Use our fully-documented REST API to send personalized letters, checks, postcards and improve address accuracy.
Felt for iPhone - Handwritten cards for the modern world