I am also looking to change the reply to when a user replies to a ticket.  By default, Odoo uses the user's email, but I need to change this to be the Helpdesk Team's email the ticket is under.  So if a ticket is created in and is under the "Support" team regardless of what user answers the customer will always receive an email from support@companyemail.  The reply still needs to relate to the correct ticket as normal.  

Thanks in advance