Event Registration - Messaging individual ticket holders

It would be nice, when someone registers for an event or product, to be able to message that person directly within Constant Contact. For example, someone bought a ticket from us, and I want to send them their QR code within Constant Contact under their purchase. That way I do not have to manually email them from my email account, hoping the email will land in their inbox rather than a random folder like Promotions or Spam.