On my iPad Air I will begin an email using Apple Mail. My settings in iOS9 are to use my default gmail address as the default email "FROM" address. During typing some emails, Apple Mail will switch the FROM address to another account at gmail. WHY???? Usually I never realize until I get a bounced email refusing to accept the sent email from the unknown mailbox address. Do we have to manually always check before sending email, or have I told Apple Mail to switch in some preference setting?