Exchange 2007 email blocking

[itwasntme]

Hi,
We allow students two methods for bringing files in to school currently (until we decide on a VLE), first method, usb pen drives, second method email.

Due to misuse of email during lessons and teachers struggling with tools such as NetSupport for blocking pages we have come to a point where we are now using transport rules to block KS3/KS4 students emailing other KS3/KS4 students.
The rules currently block (silently drop) emails sent to KS3/KS4 students from outside our organisation.
The rules currently block (silently drop) emails sent from KS3/KS4 students to anyone outside our organisation.
The rules currently block (silently drop) emails sent from member of distribution list ( KS3/KS4 email group ) to a member of distribution list ( KS3/KS4 email group ).

So basically KS3/KS4 students can email their teachers and KS5 students (on pain of being beaten up I suppose!).

This is working, and working great, except I would like to permit them access to email themselves if possible.

I realise that if Student1 were to email Student1 although they do not receive the email they will still have the mail (with any attachment) in their Sent Items.
I would appreciate hearing from anyone with any ideas how we can work the transport rules to permit Student1 to email Student1 without being able to email Student2.

Looking forward to your responses!

[Silvor]

Do I smell

[Messa]

Aye