Canary can write your emails, prioritize what needs attention, silence spam & much more. Say hello to your Inbox Copilot!

Mutt is a small but very powerful text-based mail client for Unix operating systems. Some of its features are: color support, message threading, MIME support (including RFC2047 support for encoded headers), PGP/MIME (RFC2015), various features to support mailing lists, including...

Personal Information Manager (Mail, Contact, Calendar and more).

KMail is the email component of Kontact, the integrated personal information manager of KDE. Kontact is a personal information manager and groupware software suite for KDE. It supports calendars, contacts, notes, to-do lists, news, and email.

The free Zimbra Desktop client allows you to meld the online and offline worlds – storing and synching your email, calendar, contacts, files and documents in the cloud, yet having them locally accessible when on the road.

The Bat! is a secure email client software, built to protect your correspondence against third-parties.

The open source cloud with LibreOffice online - LibreOffice online + Seafile + KDE. Improve your productivity and communicate better with your team members. The world is moving forward. Welcome to the open source cloud!.

Mail is designed to let you manage your email quickly and effortlessly. Its interface is based on conversations, so you can read an entire discussion without having to click from message to message.

Mac IMAP email client featuring keyboard control, Markdown email composition, advanced search capabilities, smart mailboxes, automatic signature handling, cryptographic options with OpenPGP/S-MIME, tagging, multiple notifications, and customizable layouts including widescreen.

Sup is a console-based email client for people with a lot of email. It supports tagging, very fast full-text search, automatic contact- list management, custom code insertion via a hook system, and more.

nPOPuk is an ultra-small, but comprehensive, e-mail client that runs on a wide range of Windows-based operating systems

TypeApp is an all-free, beautifully designed, universal email app, capable of managing unlimited number of mail accounts from various providers, allowing for smart push notifications while enabling personalization across multiple email accounts.