Below is a list of free e-mail client programs.
1) Mozilla Thunderbird
Mozilla Thunderbird is a fully featured, secure and very functional email client and RSS feed reader. It lets you handle mail efficiently and with style, and Mozilla Thunderbird filters away junk mail too
2) Windows Mail
Windows Mail is a fun and functional email program that keeps you relatively safe with spam and phishing filters while offering fast search and enough room for creativity, maybe based on ready-made stationery. Advanced filters or sophisticated tools that help you manage — and reply to — lots of mail are missing from Windows Mail, though.
3) Eudora (Sponsored Mode)
Eudora is a classic, powerful, flexible and efficient email client that cans spam precisely, too, and shows nary a weakness. Leveraging the statistical spam filter to organize good mail would be nice, though.
4) Opera
The Opera email client is a slick and flexible interface that will satisfy almost all your email needs, and Opera integrates RSS feeds in this experience as well. Some may find the message editor lacking a bit in power, and the absence of support for encrypted email is unfortunate.
5) Mulberry
Mulberry is a powerful and incredibly versatile email client available for all the popular platforms. If there is something Mulberry lacks, it is simplicity.
6) Pegasus Mail
Pegasus Mail is one of the most powerful, secure and generally best email programs available for Windows, but the interface could need some polishing to make its features more accessible.
7) IncrediMail
IncrediMail is a fun and easy to use email client that adds spice to the messages you send while protecting you from spam, phishing and fraud attempts in a convenient manner. Unfortunately, IncrediMail lacks some productivity features if you have to deal with large amounts of mail.
8) Foxmail
Foxmail is a nice email client with lots of great features that make email easy and fun. Unfortunately, it doesn't support IMAP accounts and its message editor lacks basic text (re-)formatting tools.
9) DreamMail
DreamMail manages email and RSS feeds handily and handsomely with stationery, labels and related message search. Unfortunately, international language support is limited, DreamMail's spam filter seems ineffective, and IMAP accounts are not supported.
10) Alpine
Alpine is powerful console email program that makes you use email productively with automation aplenty and nary a distraction.
11) Sylpheed
Sylpheed is a surprisingly versatile email client. 'Surprisingly' because it has a friendly, easy to use interface to its many useful features.
12) i.Scribe
InScribe and its free version, i.Scribe, are true little email program gems. They're small, fast, efficient and very usable. Unfortunately, they lack secure messaging, and the IMAP support in Scribe is not perfect.
13) Windows Live Mail
Microsoft's free e-mail program, with the familiar features of Outlook Express, plus more. It also provides spam protection and can be used with other service providers as well.