Gumroad - An all-in-one solution to sell your work and grow your audience.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Flurly - The easiest and most affordable way to sell digital products online
Aqua Mail - Android Mail Client.
Streak - Manage customers inside Gmail
FairEmail - Open source, privacy friendly email app