What's the best email service for kids?

[Lordchoc]

I'm trying to find the best email service for my 9yo (about to be 10yo).
I think I want the following things:

1. the option to have a copy of all email to my account
2. a 'safe' contacts list - and approval by me for new people
3. both parents to have control
4. offensive word filter
5. works with Mac Mail
6. attachment approval/blocking eg yes to all pdfs but no to jpegs
7. a decent email address eg ending in .com or preferably .co.uk

KidsEmail looks good apart from point 7.

Any other suggestions/tips welcome. Thanks.