SurfBuddies Mail - description from Softdepia.com:
SurfBuddies Mail is a Windows based POP3 email client. It is designed to run on your computer and access POP3 email accounts provided by SurfBuddies, your ISP or other POP3 email hosting services. By running on your local computer, you are assured that your child's information is under your control at all times.
With SurfBuddies Mail and an internet connection, your children can safely send and receive email messages with friends, family and organizations you approve. Only those messages from people in the parent defined Buddy List will be displayed. SPAM and messages from questionable sources are not an issue with SurfBuddies Mail.
SurfBuddies also includes Microsoft Agent technology which displays animated characters who can read a child's email out loud. Kids love it!
SurfBuddies Mail is a "Free to try" program. You can download and try it for an evaluation period.