Mailmeteor - Send hundreds of personalized emails with Gmail.

Postalytics - Automated direct mail software that’s faster, smarter & better. Postalytics sends personalized direct mail from your CRM and analyzes delivery & response.

GMass - GMass allows you to easily schedule emails, send out mass emails and mail merge campaigns and more with Gmail! Click here to learn about more features!

Lob - A simple API to integrate print & mail solutions into your applications.

Interseller - Interseller helps find contact information, reach out to them with email automation and syncs it all into your database.

AmazingMail - Business print-mail solution