Newton Mail - Newton is a fully featured mail client available for Android, iOS, macOS and Windows.
myMail - myMail is the smart email app for managing all your accounts on iOS and Android.
Gmail - Gmail is available across all your devices Android, iOS, and desktop devices. Sort, collaborate or call a friend without leaving your inbox.
FairEmail - Open source, privacy friendly email app
K-9 Mail - K-9 is an opensource email client making it easy to chew through large volumes of email.
Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.