How do I change from a group to a standard email

How do I change from a group to a standard email

I'm trying out the service and initially setup a "Group" with the email "contact@example.com". I decided that I'd rather have this email address be a basic user account so I deleted the Group and added "contact" as a user. The system won't let me associate the "contact@example.com" email address with the individual user account. It says the email already exist, but it doesn't show up under Mail Administration -> Mail Accounts in the Control Panel or anywhere else that I can see it. 

Is it possible to make this change?