TLDR: We built out an API for sending handwritten letters at https://www.handwrite.io/handwritten-notes-api Quick backstory: I was helping a small moving company build out some marketing automation as a side gig. We were ingesting housing data and as soon as a house went up for sale, we'd use lob.com to send a direct mail postcard letting the home owner know we'd love their business. But the postcards didn't convert well, and were super cliche so I went searching for something that might feel a little more personal. That's when I met my cofounder, Dan, here on Hacker News!…