What are some alternatives?
Mailpile - Mailpile is a modern, fast web-mail client with user-friendly encryption and privacy features.
Gmail - Gmail is a free search-based web-mail service.
Roundcube - Web-based IMAP email client
ProtonMail - Secure email with absolutely no compromises. Get your free encrypted email account today.
NeutronMail - Self-hosted server for the ProtonMail client.
Zoho Mail - Zoho Mail is a webmail service built with the needs of a modern business in mind.