I've been setting up a new iPhone 6s (restored data from old phone via iTunes on Macbook) and it seems to have affected my Google mail on phone and laptop. On laptop, I can get into Google mail if I log in via Safari but when I try to enter password via my mail account settings it says it's failed to authenticate, however I can receive emails sent to Google email in mail but not send from it. When I input password for Google on phone I get a page saying iOS would like to manage mail, view basic profile, manage calendars, manage contacts etc. Whether I press deny or allow it then says "the email address you entered does not match your account", even though the email addresses are the same! I can't receive or send from my Google email on the phone. My BT account seems to be fine on both devices. Help much appreciated.