1. When the two accounts (drupal and google) are created and the user wants to login it says email doesn't exist, I noticed it happens only when the user is new and has not accepted the email address (which the user can't do with googleauth module).
2. When a user tries to login using http://mail.google.com/a/domain.com directly and it gets redirected to http://www.domain.com/googleauth/signin it always says Access Denied even if the module has enabled access to every user but anonymous.