Where is this %$#@ Function in the 8.5.1 mail template?!?!

Please accept my humblest apologies for my language, but I’ve a VIP who is simply asking to have the ‘Remove from folder’ function in his mail template button/action bar [the one above his Inbox view, which is associated with the folder icon] removed so he doesn’t accidentally hit it again for the 11teenth time, and I have no idea where that sucker is, nor how to purge it using the Designer client.

Can someone very kindly point me to the right location so I can remove it from the button bar, please?

Thanks in advance!

Subject: it’s in the ($Inbox) folder design

remember to turn off inheritance.