When you're deploying POP3 for Exchange Server 2010 you'll generally need to configure the email client settings manually. Even though you can make things a little easier by publishing the POP3 client settings where users can find them they will still need to set up their email client with the correct settings.
Windows Live Mail is one email client that works with Exchange Server 2010 POP3. You can download it as part of the Windows Live Essentials pack (you don't need to install all of the applications in the pack if you don't want to).
When you launch Windows Live Mail it will begin the new email account wizard if there are none already configured. Enter the email address, password and display name for the account you want to set up, then click Next.
Click Finish to complete the new account setup.
Windows Live Mail will connect to the Exchange server and download new mail items.
By default Windows Live Mail will leave a copy of all downloaded email messages on the server, which is how most people would prefer it to be configured. If you wish you can turn that off in the account properties so that downloaded emails are removed from the server.
When copies of messages are left on the server it is important to be aware that when the POP3 client downloads new emails they are marked as read in the Exchange mailbox. Similarly, messages that have already been marked read in the Exchange mailbox will appear as unread in the POP3 client when they are first downloaded. There is also no synchronizing of the read/unread status of messages between the Exchange mailbox and the POP3 client.