Contact Attachments come through as e-mail attachments

A friend of mine is trying to send me a bunch of contacts from his
Outlook 2007 profile. He goes to the Contacts folder which is viewed
as "Business Cards" Selects all and drags them into an e-mail
message. He addresses the e-mail message to me and sends it. We are
both on the same Exchange Server. Last night through OWA, I looked at
the e-mail and the attachments were there AS contacts. i.e. if I
double clicked them, they showed all the contact fields, etc.

This morning, I popped open my laptop and downloaded my mail (We use
POP) which also removes the messages from the server. When I opened
the e-mail, all of the contact attachments showed up with an e-mail
envelope icon and not a contact icon. When I double click the
attachments, it is just a blank e-mail message.

How can I prevent this from happening?

Thanks!
John