This document explains how you can use a custom BADI to enable or disable all reply options such as: Reply, Forward, or Reply with Outlook in the Ticket Interactions. Additionally, you can set the To Address by using this BADI you can set a default address as Sender of the email.
Further details about this feature here.
SAP Cloud for Customer
To achieve these settings you will need to enhance the standard C4C using a BADI via the SDK software.
The BADI below is the one that must be activated to use this feature.
Once you activate it the changes will be applied to both (HTML5 and FIORI) UI's.
BADI; E-mail; Communication; Interaction; , KBA , LOD-CRM-SRP , Service Request Processing , How To