Noisli - Noisli is a fantastic background noise and color generator for working and relaxing. Online soothing ambient sounds like White noise, Rain and Coffee Shop.

Mailspring - Mailspring is a mail client for Mac, Windows and Linux.

Noizio - Feeling that the noise of the big city is too much for you to bear?

Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

MyNoise - Custom shaped online noise machines. Many Many generic sounds

The Bat - The Bat! is a secure desktop email client for Windows, designed to protect your correspondence against third-parties and to save your time.