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.
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.
Mailbird offers a solid and reasonably productive email experience. You get to try it for one account in the free version while (good) multi-account support is reserved for the paid version.
While Mailbird is extensible with “apps”, these usually do not integrate well, and email handling itself can feel limited to the basics.
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.
IncrediMail is a fun and easy to use an 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.
Mail for Windows
Mail for Windows is a basic email program that lets you handle email in multiple accounts with ease and security, though it lacks more sophisticated features.
You cannot set up filters, for example, email groups or message templates.
Mulberry is a powerful and incredibly versatile email client available for all the popular platforms. If there is something Mulberry lacks, it is simplicity.
Foxmail is a nice email client with lots of great features that make email easy and fun. It includes a way to send large attachments but does not unify inboxes across accounts, for example.
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.
Alpine is powerful console email program that makes you use email productively with automation aplenty and nary a distraction.
Sylpheed is a surprisingly versatile email client. ‘Surprisingly’ because it has a friendly, easy to use interface to its many useful features.
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.