Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Mailwasher - Over 8 million people use MailWasher as their spam filter
Microsoft Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
SPAMfighter - SPAMfighter and Microsoft have built the strongest and most effective anti spam filter for Outlook, Windows Live Mail, Outlook Express & Thunderbird
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.
Spam Reader - Spam Reader is a free anti-spam add-on for Microsoft Outlook.