I have two computers for use only by the kids. They have instant messenger clients on them, but I also have Zone Labs IMSecure to protect the client and Ihave a web content filter, eBlaster and VNC installed so I can monitor all activity on the machines.

I would like to set up email for them, but I don't think they should get 20 emails a day for Viagra, low mortgage rates or how to increase penis size. Does anyone know of an email client- cheap or free- that will let you work on a white-list only basis?

In other words, I want ALL incoming mail blacklisted by default, and only the one or two email addresses I specify on the whitelist will be allowed through.

Any ideas?