Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
My Personal Kanban - This is a one page HTML/JavaScript application for people who would like to use simple and basic...
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
TaskBoard - A Kanban-inspired app for keeping track of things that need to get done.
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.
buckets.co - Feature rich kanban board collaboration platform.