Mozilla Thunderbird makes emailing safer, faster and easier than ever before with intelligent spam filters, a built-in spell checker, extension support, and much more. A portable version is also available.
Foxmail is a free lightweight email application that offers you many useful features and a user-friendly interface and supports POP3 accounts, as well as Hotmail accounts, with support for HTML email, mailbox encryption, multiple accounts and more.
Howard Email Notifier will keep you notified about new emails in your outlook.com, live.com, hotmail.com, mail.google.com, mail.yahoo.com, facebook.com, LinkedIn, twitter.com, e.mail.ru, orange.fr, IBM / Lotus Notes, mail.virgilio.it, O2.pl, Yandex, Laposte.net and www.zoho.com inbox.
KLS Mail Backup is a straightforward app that permits the backup and restoration of most of the popular email clients, including Mozilla Firefox, Thunderbird, Windows Mail, Outlook Express, among others.