Our recommendation list contains email clients that support both OpenPGP and strong authentication such as Open Authorization (OAuth). OAuth allows you to use Multi-Factor Authentication and prevent account theft.
Email does not provide forward secrecy
When using end-to-end encryption (E2EE) technology like OpenPGP, email will still have some metadata that is not encrypted in the header of the email.
OpenPGP also does not support forward secrecy, which means if either your or the recipient's private key is ever stolen, all previous messages encrypted with it will be exposed: How do I protect my private keys?. Consider using a medium that provides forward secrecy:
Thunderbird is a free, open source, cross-platform email, newsgroup, news feed, and chat (XMPP, IRC, Twitter) client developed by the Thunderbird community, and previously by the Mozilla Foundation.
For iOS devices we suggest Canary Mail as it has PGP support which means you can send end-to-end encrypted email.
Apple Mail is included in macOS and can be extended to have OpenPGP support with GPG Suite, which adds the ability to send encrypted email.
Evolution is a personal information management application that provides integrated mail, calendaring and address book functionality. Evolution has extensive documentation to help you get started.
Kontact is a personal information manager (PIM) application from the KDE project. It provides a mail client, address book, organizer and RSS client.
Mailvelope is a browser extension that enables the exchange of encrypted emails following the OpenPGP encryption standard.
K-9 Mail is an independent mail application that supports both POP3 and IMAP mailboxes, but only supports push mail for IMAP.
Canary Mail is a paid email client designed to make end-to-end encryption seamless with security features such as a biometric app lock.
Canary Mail only recently released a Windows and Android client, we don't believe they are as stable as their iOS and Mac counterparts.
Canary Mail is closed source. We recommend it, due to the few choices there are for email clients on iOS that support PGP E2EE.
NeoMutt is an open-source command line mail reader (or MUA) for Linux and BSD. It's a fork of Mutt with added features.
NeoMutt is a text-based client that has a steep learning curve. It is however, very customizable.