Sparkpost - Deliver your app and website emails on time and to the inbox. Trusted to send 25% of the world's non-spam email. Email delivery for companies big and small.
Email Inspire - Discover the best of email design and marketing — Browse email newsletters from top brands.
SocketLabs - Marketing & transactional email delivery platform
EmailWay - Collection of the most insightful and informative email newsletters from across a wide spectrum of industries and interests
Return Path - Inbox placement solutions from Return Path helps improve email deliverability and increases email marketing ROI.
Really Good Emails - A large collection of good product email design.