This decision is really up to you. There are many e-mail "clients" available in the market today. Here is a list of the more commonly used clients for Windows:

• Outlook - A powerful e-mail and scheduling client made by Microsoft. It is generally recommended for advanced e-mail users.
  
• Outlook Express - A smaller, less powerful, version of Outlook. It's condensed functions use less RAM and make it easier to use.
  
• Netscape Mail - The native mail program for the Netscape browser. It's simple interface and ease of use, makes it a fan of many.
  
• Eudora - An e-mail program written by Qualcomm. It's small, powerful, and somewhat complex. Not recommended for beginning users.
  
• Pegasus Mail - A small yet powerful and relatively unknown e-mail client. Although relatively primitive in it's first releases, later versions have come a long way up the ladder of user friendliness.
  

The Outlook program from Microsoft is not only an e-mail client, but a powerful scheduling tool as well, which many find useful. These many clients all perform the same function, sending and receiving e-mail, but will accomplish it in a variety of different ways. All of these clients support multiple accounts, which allows you to check multiple e-mail addresses at one time. They all support "Message Rules" which allow you to specify the way that your messages are organized. Outlook Express and Pegasus Mail will create multiple "Identities" which allow a number of users to use the same client but not access one another's e-mail. All of these e-mail clients have address books, sent item histories, off-line capabilities, and the ability to choose the format in which your mail is sent.