How is it going to forward to your email? To copy direct to an email folder it needs access to the account. To send from one of your accounts it needs that account'a login. You are making an assumption about how it would work (upload text to a server and then send it to you as an email from there), but that is not the only way such a thing could work, and clearly not the way it does.
Maybe they figure that what you were assuming would be unpopular because every text notification would be followed by an email notification, whereas with the account login they can copy it silently?
If you don't want to give it that access (which I can understand) then just don't.