Ticket conversation issue

Ticket conversation issue

When a new ticket is created a technition is able to click the reply option and type a message to the requester.  The requester receives that reply as an e-mail in their inbox (from helpdesk@mdrt.org), and the reply is also logged in ManageEngine.  However when the requester responds to that reply message, the reply never reaches ManageEngine and the response instead is sent as a normal e-mail to the corresponding inbox ( helpdesk@mdrt.org).  This used to work correctly - when a requester would reply to the reply message it would go back to ManageEngine and show up there in the conversation area of the ticket.

Is there an option that needs to be enabled to get this functional again?

Thanks!