Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!

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

Postbox - The Power Email App for busy professionals, like you.

Newton Mail - Newton is a fully featured mail client available for Android, iOS, macOS and Windows.

Claws Mail - Claws Mail is an email client (and news reader), based on GTK+, featuring Quick response

myMail - myMail is the smart email app for managing all your accounts on iOS and Android.