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
MailTamer - Don’t get buried in mountains of emails and let them get control of you and your inbox again!
Mastermind Manager - Software for running mastermind groups
myMail - myMail is the smart email app for managing all your accounts on iOS and Android.
ProtonMail - Secure email with absolutely no compromises. Get your free encrypted email account today.
K-9 Mail - K-9 is an opensource email client making it easy to chew through large volumes of email.