Spark Mail - Spark helps you take your inbox under control. Instantly see what’s important and quickly clean up the rest. Spark for Teams allows you to create, discuss, and share email with your colleagues
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
FairEmail - Open source, privacy friendly email app
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.
K-9 Mail - K-9 is an opensource email client making it easy to chew through large volumes of email.