Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Spike - Spike solves businesses' communication chaos by bringing together email, team chat, collaborative docs, and meetings, into one feed.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Front - The platform for exceptional customer service at scale.
eM Client - eM Client is a fully-featured email client for Windows and macOS with a clean and easy-to-use interface. eM Client also offers features for calendars, tasks, contacts, notes, and chat.
Missive - Team communication app now supporting FB, Twitter & SMS