At work we share contact information by dragging a contact from the contact
folder to an email and then sending the email. The recepient then drags the
contact from the emailto his/her contacts. I have tried to do this to my
home email and it doesn't seem to work.

I create an email in Outlook 2003 (XP) and drag a contact to it. I then
send the email to my home address.

When I receive the email at home, Outlook 2007 (Vista), it looks like that
contact is attached but when I open the email the attachment is another email
(envelope symbol). When I open this it is simply an email with the contacts
name as the subject line.