Really Good Emails - A large collection of good product email design.
Mustr - Mustr is a public relations platform that helps the media team in organizing the network of journalists and bloggers and maintaining relations with them.
Email Love - Email design inspiration, templates and discovery
Exposely - Immediately reach the largest audiences.
Stamplia - High converting and beautifully designed email templates
Crowdly - Crowdly is a social advocate management platform, helps brands find, rank and engage their top advocates on Facebook.