I'm trying to change "When replying to a message" (card "Accounts", section "Send mail as") to "Reply from the same address to which the message was sent" in Gmail Settings" by Gmail API (using service account that was delegated domain-wide authority) and I cannot find it in the docs (https://developers.google.com/gmail/api/v1/reference/users/settings/sendAs).
To explain why I want to do this: I'm adding certain role based Google Groups my users are member of to their send email as preferences (by the service account with domain wide authority). For example, users responsible for dealing with legal@ address are member of Google Group called legal and they have legal mails in their mailbox. When responsible users change, I just change the membership and new users receive the mails. The problem is that just the first email comes to legal@ and reply goes from john.smith@ for example. Because of that, I decided to have them reply from legal@, so those who requests something from Legal Departament knows they are communicating with whole Legal Departament and not Mr Smith only. But when Gmail doesn't automatically choose correct address when replying to the legal mail, it doesn't do what I'm trying to do.
It doesn't matter for me if I change it in admin console or by script running on all users. I wasn't able to use any of those ways.
Thank you for your help, Martin
