You might say that an email client can only be as funny as the emails you get. But still it's more fun to read and write electronic mail with some email programs than it is with others. Here are the least boring ones for Windows.
Windows Live Mail itself is not a spectacular program. But there is so much so wonderful stationery available for it, making Windows Live Mail the most fun email program for sending (and receiving) gorgeous messages. (In versions of Windows prior to Vista, Outlook Express is a similar program.)
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.
WikMail is a multifarious email tool that includes mail checking, a fun email client, postcards, tools to create stationery and a lot more.
Foxmail is a nice email client with lots of great features that make email easy and fun.
AOL's email service is easy to use, and it comes with many elements of fun: stationery, banners, greetings, sounds,...
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.
7. Express Plus
Support for rich HTML formatting, stationery, instant iconic identification of known senders and other nice features make Express Plus a pretty funny email client.
8. LCARS Mail
LCARS Mail is a pretty dull email client — if it wasn't for the great Star Trek-like LCARS interface.
PocoMail is primarily a sophisticated email client for users who have to handle large volumes of mail efficiently — but it can also be a lot of fun, and its skinnable interface can be customized and tweaked as you like it.
Eudora is pronouncedly staid and functional, but it is not boring. MoodWatch can be a hilariously funny feature, for example, and using PureVoice you can send voice emails.