Designjar - Designjar offers graphics for social media and online advertising.
Good Email Copy - Email copy from great companies.
Zurb - ZURB helps companies design better websites, services and products through services that include design strategy and interaction design.
Free Marketing Email Copy - Marketing email copy from 500+ popular brands.
Raven Creative - Raven Creative specializing in effective, strategy-driven solutions for website design, branding, advertising & beyond.
Really Good Emails - A large collection of good product email design.