Thunderbird is a free, open source, cross-platform e-mail, news and instant messaging client. The project strategy is modeled after Mozilla Firefox.
Thunderbird vs Geary opinions
I don't like thunderbird at all!
Its more flexible, stable, and with extensions incredibly powerfull.
cross-platform support, more functionality
Microsoft Outlook, part of the Microsoft Office Suite (not to be confused with Microsoft Outlook Express), is a personal information manager that lets you manage your e-mail, calendar, contacts, and tasks.
Microsoft Office Outlook vs Geary opinions
Outlook = MAPI-centric, has only very minimal support for IMAP/POP3.
Boost your productivity and send better email with Mailspring, a beautiful, fast email client for Mac, Windows, and Linux. Mailspring is free to use and an optional pro version adds read receipts, send later, reminders and more.
Mailspring vs Geary opinions
Geary, EM Client and Mailspring make good alternatives for those used to original versions of Outlook.
Postbox is an email application that helps you organize your work life and get stuff done.
eM Client is a full featured e-mail client with a modern and easy to use interface. eM Client also offers calendar, tasks, contacts, notes and chat.
eM Client vs Geary opinions
One of the best email clients for Windows. Has it all: POP, IMAP, Exchange, Gmail, Outlook and others, Jabber, Google Talk, calendars (Fruux and CalDAV support included) and of course contacts (every major platform plus Fruux and CardDAV). Fast, nice search features, no much bugs...
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...
BlueMail is a modern, mobile first, powerful Email management tool with a sleek design, unified inbox and support for all your accounts: IMAP,Exchange,POP3.
BlueMail vs Geary opinions
BlueMail is my favorite email client on Android. Tons of features, and no ads.
Canary is an exciting new email client for Mac that offers a full set of powerful features with one key difference - your emails are not stored on a 3rd party server.