PostGrid has been great for automating our insurance mails for our client
Lob - A simple API to integrate print & mail solutions into your applications.
Thankbot - Drive more business with handwritten notes
Postalytics - Automated direct mail software that’s faster, smarter & better. Postalytics sends personalized direct mail from your CRM and analyzes delivery & response.
Handwrytten - Handwritten notes straight from your device. Huge selection of cards or design your own. Handwriting service integrates with 1000's of apps.
AmazingMail - Business print-mail solution
Felt for iPhone - Handwritten cards for the modern world