Gumroad - An all-in-one solution to sell your work and grow your audience.
Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Flurly - The easiest and most affordable way to sell digital products online
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Streak - Manage customers inside Gmail
K-9 Mail - K-9 is an opensource email client making it easy to chew through large volumes of email.