Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
BlueMail - BlueMail is an email management app for Android, iOS, and Windows.
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Junk Email Filter - Junk Email Filter is a front end spam filtering and virus blocking service for email servers.
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.
Covideo - Covideo is a Video Email Platform for Businesses that enables companies to communicate quickly and effectively with their customers.