Set default Email for Outgoing Case Responses

Hello

We have a support email address to receive all incoming emails and then convert them to cases which works fine. We want all outgoing responses go via same address so client don't see the individual address but only the support address. How can we make the default sending email address for all user to be the support email address when they reply to emails? We can select the from Address manually and select the queue but how to make the from address as default to be the Support email address.

Thanks in advance to provide right steps.