Easy: Need spam proof email for a child

I am setting up my 11 year old brother in law with his first computer and hence: his first email account. However, after deleting all the spam out of my hotmail account this morning, I hesitate to set him up there.
I am looking for a FREE email service that can provide some insulation against the xxx rated, insurance scams, diploma offers, and of course…viagra sales.
Can anyone provide some insight. Perhaps a link to a service with some proof of its child proof nature?

Thanks.