IMO, Incredimail is sort of the ultimate in Fisher Price type programs. Lots of bright pretty colors, flashy animations, and an interface designed with a 3-year old as the primary user, all designed to distract you from the lack of any real substance. Microsoft is no doubt taking notes for the next version of Windows.
Personally, I've taken to using Thunderbird (http://www.mozilla.org) for pretty much all my email. It's free, it's powerful, it's reasonably intuitive, and it runs on Windows, OS X, and Linux so I can have the same program no matter what system I'm using.
Eudora Pro is probably my second choice. No Linux version, but there is a Windows and Mac version.
Mail.app is quite nice for OS X only, and The Bat for Windows has a certain Spartan appeal to it. Of course I've really become a fan of Google's Gmail, and have been using it exclusively lately. Unlike most web email setups, Gmail's interface is based on DHTML so it's very fast. It's light on the graphics (just the Gmail logo), and the ads are all text and positioned unobtrusively. And with 1000MB storage, I don't need to worry about exceeding a paltry 2-4MB quota. To top it all off, all I need is a web browser and an Internet connection to access it.
I have used Outlook Express for years and I personally love the program, most of the time. I also like IE. Windows XP and OE6 however, seemed to end the days of being able to switch identities with impunity; now the system crashes and I lose access to both email accounts, and the tips to fix the problem do NOT work for my computer. I've repeatedly had problems even after Gateway said it was all fixed. So now I use OE6 for my business email and Roadrunner webmail for my personal email (a pain).
I have tried eudoramail, netscape, and pocomail and wouldn't wish any of them on my worst enemy. I want something simple to set up multiple signature lines and that works like OE. Roadrunner told me I could have 2 different email client programs without messing things up, so I was planning to download Incredimail. Incredimail beta a few years ago kept crashing, but I've heard good reviews from friends lately, but I did notice a warning in another post NOT to download it. Why?
OK. What should I use, that works like OE, AND WHY please?
Is there any forum on this subject already?