edit in compose email in the service operation workspace

[salaheddinezaf1]

hey i have an issue i want to edit in compose email in the service operation workspace ex :
when i receive an email based on the incident record there is the reply button like bellow in the image  all what i need is to find where this button stored to edit on it 

[Leavatin]

I have been trying to figure this out as well but I still could not find the config for this one the only close to is that I could find is on sys_ux_app_config.