First, 1.9 is pretty old. You need to be on 1.9.5.1.-customer reply's to my email (directly, not using OS Ticket GUI)
I don't understand why the customer got a reply from your email address. Does osTicket use your email address? If so, that may be a problem. But even so, osTicket should be fetching that reply and adding it to the ticket.Do you have email fetching set up?You really need to help us with some info. Please seePlease read before requesting assistanceThen reply with the info that is requested.Jack