Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
SOGo - SOGo is groupware server with a focus on scalability and open standards.
Mailbird - Mailbird is the best email client for Windows 7, 8 and 10
Baïkal - Cal and CardDAV server
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.
Radicale - The Radicale Project is a complete CalDAV (calendar) and CardDAV (contact) server solution.