http://riseup2a3go3phwiacrkq35qj2mjuankua4oxbu3b6nwil77soa5k6qd.onion/en/email/clients/thunderbird
As Free Software, Thunderbird is part of the digital commons, a kind of common treasury for all. Outlook, on the other hand, is Microsoft’s tool for world domination. Thunderbird has many features, including: IMAP and POP support, multiple accounts, quick search, spell as you type, advanced spam controls, RSS , virtual folder views, message filtering, addressbook, and support for OpenPGP encryption.