What are some alternatives?
Gmail - Gmail is a free search-based web-mail service.
Thunderbird - Thunderbird is a free email application that's easy to set up and customize - and it's loaded with great features!
Outlook - Organize your world. Outlook’s email and calendar tools help you communicate, stay on top of what matters, and get things done.
Newton Mail - Newton is a fully featured mail client available for Android, iOS, macOS and Windows.
Mailspring - Mailspring is a mail client for Mac, Windows and Linux.
myMail - myMail is the smart email app for managing all your accounts on iOS and Android.