Which Email Program is the Best?
The answer will never be the same for everyone. The real answer is 'it depends on what you need'.
Outlook Express is included in earlier versions of Windows including Windows XP. A version of Outlook Express is still in Vista, going by a new name, Windows Mail. More than likely this email client is used more than any other, simply because it comes with Windows. There are some security issues with Outlook Express, but if the program is configured properly it is as safe as the user allows it to be. (No email program is safe if users open spam mail, click on links from unknown senders and generally use bad email behavior.) Outlook Express very adequately handles the email need for the majority of folks, and it is free because it comes with Windows.
Microsoft Outlook is part of Microsoft Office. It is not free and in fact costs more than just about any commercial email program. Much confusion has been caused because MS gave two totally different programs a very similar name. MS Outlook is more than just an email program. It has a very full featured calendar complete with reminders. It has a journal and a nifty feature, notes.
Windows Mail is the name Microsoft gave Outlook Express in Vista. Windows Mail has a different look and feel but it is basically the same program as Outlook Express. It has some underlying changes and not all for the better, but it will still handle email quite well for most folks. It has proved to be a tad buggy in some cases.
Windows Live Mail is a free downloadable email from Microsoft. It also proved to be buggy for a lot of users, however the latest version of WLM, Windows Live Mail 2011, is much improved and should work for most users. It can be a bit daunting to use at first as Microsoft changed the interface to use the ribbon. Once you learn where stuff is located, it is pretty cool!
Windows 7 doesn't have an email program. If you read your email on the web, then no program for email is necessary. However, if you have emails you want or need to keep, then it is advisable to download them to an email program on your computer and make regular backups to external media.
I have used a number of email programs and there are things I both like and dislike about all of them, but MS Outlook is still my favorite.