Teachable - Create and sell beautiful online courses with the platform used by the best online entrepreneurs to sell $100m+ to over 4 million students worldwide.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Clever - syncing between education applications for K-12 schools
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Claroline - Claroline is a collaborative eLearning and eWorking platform.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.