Pegasus Mail!

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.

Mailbird is a Windows based email client which design and style match Windows 7, 8 and XP’s native styles. Mailbird provides clean, simple and lightning fast email experience.

EssentialPIM lets you manage appointments, tasks, notes, contacts, password entries and email messages across multiple devices and cloud applications.

Open365 is an Open Source, self-hosted file sync and cloud apps platform including a full LibreOffice Online. You can also access your email, calendar and contacts using KDE Kontact. Everything is accessible from a simple webpage using any HTML5 browser.

Icedove is the Thunderbird email client rebranded by Debian .

Windows 10 has Mail and Calendar apps already built in.

A fully fledged, free email server solution, an open source project (GPL v2).

Foxmail is a free POP3 and IMAP4 e-mail client in English and Chinese for Windows systems.

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. It uses KParts to embed the various applications (KMail, KAddressBook, Akregator, etc.) into the container application.

Becky! Internet Mail is an email client for Windows OS. Becky! Internet Mail supports POP3, IMAP and S/MIME as well as PGP/PGP via add-ons.

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

Indian Webmail service allowing people to sign up for an @email.biz mail account.Cloud based Login and Multiple Login System give you safe and secure access to your POP / IMAP email accounts. Now access your email with any Web Browser, PDA or Mobile phone from anywhere in the world.

Fast, good looking email client. Lighter than MS Outlook with some unique and clever features.You can use Hiri to connect to Exchange, Office365, or a Microsoft email account (Outlook.com, Live, Hotmail). Other email providers, such as Gmail, Yahoo, etc are currently not supported.