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.

Mockaroo - A realistic data generator to test your app

Mailivery - Reach the Inbox, not the spam folder.

JSON Generator - Create mock and sample JSON using a powerful template syntax

Postal - Open source mail delivery platform, alternative to Mailgun or Sendgrid

Softbuilder SB Data Generator - SB Data Generator is a simple and powerful tool to generate and populate selected tables or entire databases with realistic test data.