Mailgun - A set of powerful APIs that enable you to send, receive and track email from your app effortlessly whether you use Python, Ruby, PHP, C#, Node.js or Java.

Sellbery - Easily automate product feeds from Shopify, Magento to Amazon, eBay and other marketplaces. Fully utilize the most profitable eCommerce channels and increase sales.

MailChimp - MailChimp is the best way to design, send, and share email newsletters.

eBay Enterprise - eBay Enterprise provides a variety of marketing, customer care, payment processing, fulfillment, fraud detection services.

SendGrid - Learn why more developers choose SendGrid for their email deliverability service to send transactional emails triggered by web apps. Get started for free

Radial - Radial offers order management and store fulfillment solutions.