Automated Email Workflow for Re-Engagement

Traffic to our store is strong, but we’re under-leveraging the warmest segment we have—previous customers. I want an automated email workflow that zeroes in on getting past customers to buy again, then rings in new visitors and cart abandoners into the sequence as well... (Budget: $250 - $750 USD, Jobs: A/B Testing, Customer Retention, Customer Retention Marketing, Email Campaign, Email Marketing, Google Analytics, Magento, Mailchimp, PHP, Software Architecture)