Hi, Kelly
If these email receipts have the same Subject line, you could create a new group within a department and then set up an Event to automatically transfer tickets with that Subject line to the new group.
Quickly, the Category would be "Tickets" and the Type would be "Ticket Message Received".
For your Conditions, you'd want to, at the very least, check "Subject" and then set its parameters. For example, Subject -> Equals -> Receipt for Recent Purchase
For your Actions, you'd select Transfer Ticket, set the Frequency, then select the Group you want the ticket transferred to. You can even assign those to a specific agent in that group if you want.
I hope that helps.
Derek Curtis
COO
SmarterTools Inc.
www.smartertools.com