I'm able to add a "Send mail as" email address via the API. I need to set "Reply from the same address to which the message was sent" so that when mail comes in from that address, mail goes back out with that address as the sender. How can we set this via the API?
Is it possible to set this for all mailboxes within a Google Workspace account? Either would be fine for me, either individual user or at admin level as policy for every user.
Currently there is no option to configure "Reply from the same address the message was sent to" through the Gmail API or the Google Workspace Admin console, only users can do it through their side.
These are the only fields available to configure within the "Send mail as" feature through the Gmail API.
This is a product limitation for Gmail API, this request can be promoted for future development through here.