When requiring an email address for guests and the host on the new event registration form, you might notice that acknowledgement emails addressed to the host are being sent to the host and the guest.
We are currently evaluating this issue for a fix in a future service pack.
Steps to Duplicate
1) Create a new event registration form with the email address field required for the host and guest. 2) Register for the event as one constituent, Example A (the guest), while checking out as a different constituent, Example B (the host). 3) Notice that the acknowledgement email is addressed to Example B but sent to both constituents.