Squarespace Email Campaigns - Email, but pretty.
HubSpot - Grow Better With HubSpot: Software that's powerful, not overpowering. Seamlessly connect your data, teams, and customers on one CRM platform that grows with your business.
Lob - A simple API to integrate print & mail solutions into your applications.
MailChimp - MailChimp is the best way to design, send, and share email newsletters.
PostGrid - Transform your Offline Communications. Use our fully-documented REST API to send personalized letters, checks, postcards and improve address accuracy.
Marketo - Marketo's powerful marketing automation software helps marketers master the art & science of digital marketing to engage customers and prospects.