Gnu Privacy Guard (GPG) is free and open source software capable of encrypting, decrypting and digitally signing messages and files. An email client is an application that lets you download and manage your messages - from multiple accounts with multiple providers - without a browser. Thunderbird is a free and open source, cross-platform email client for sending, receiving and storing email. For this latter case, we will recommend alternative settings in the relevant sections. You can still use Thunderbird as your regular mail client, and we recommend it if you prefer to download your email to a secure device instead of leaving it in the servers of your email provider.
This guide is recommended for a specific use case, in which you only use Thunderbird as a tool for email encryption, while reading and sending unencrypted email through their webmail interface in a browser or through a different client. The ability to read and compose messages while disconnected from the Internet.The ability to manage multiple email accounts using a single tool.The ability to make sure that you are encrypting your email only for the intended recipient/s.The ability to digitally sign your emails and authenticate signed email from others.
KeePassDX - Mobile Password Manager for Android.