Sidemail - The simplest way to send transactional emails. Sidemail makes sending transactional emails trivial, it's perfect for side projects, MVPs or the next big thing.
Startup Stash - A curated directory of 400 resources & tools for startups
PromoTab - This tiny tool uses a real Gmail account to check if your emails will land in the Primary inbox of a reader or if it's stuck in the promotions tab or SPAM folder.
Content Marketing Stack - A curated directory of content marketing resources
Postal - Open source mail delivery platform, alternative to Mailgun or Sendgrid
StartupResources.io - Tightly curated lists of the best startup tools