Mailchimp is a marketing automations platform that enables marketers seeking to promote via email, social, landing pages, postcards, and more — all from a single platform. Mailchimp, founded as an email platform for small business, now includes a Marketing CRM, audience dashboard, the ability to tag and segment data, an address finder, predicted demographics, lookalike audience finder and personalization tools.  

Mandrill is a reliable, scalable, and secure delivery API for transactional emails from websites and applications. It's ideal for sending data-driven transactional emails, including targeted eCommerce and personalized one-to-one messages.