Right, i've been through the Firebase IOS Swift documentation and still cant find the answer i'm looking for.
In my SignUp ViewController:
 if let userName = self.userName.text where userName != "", let email = self.email.text where email != "", let password = self.password.text where password != "" {      
  DataService.dataService.BASE_REF.createUser(email, password: password, withValueCompletionBlock: { error, result in
    if error != nil {
      print(error)
    } else {
      // CREATE AND LOGIN THE NEW USER WITH AUTHUSER
      DataService.dataService.BASE_REF.authUser(email, password: password, withCompletionBlock: { error, authData in
        let user = ["provider": authData.provider!, "email": email, "username": userName]
        DataService.dataService.createNewAccount(authData.uid, user: user)
      })
        NSUserDefaults.standardUserDefaults().setValue(result ["uid"], forKey: "uid")
        //PERFORM SEGUE TO LOG USER IN
        self.signUP.animate(1, completion: {
          let myTabbarController = self.storyboard?.instantiateViewControllerWithIdentifier("myTabbarController") as! UITabBarController
          let appDelegate = UIApplication.sharedApplication().delegate as! AppDelegate
          appDelegate.window?.rootViewController = myTabbarController
          myTabbarController.transitioningDelegate = self
        })
      }
    })
  } else{
    self.showErrorAlert("All fields are required", msg: "Please sign up")
  }
}
When user imput email such as a@a.com, the console accepts. I though the server side would handle this. Similarly, when i generate a code to handle this issue such as :
   // FUNC TO VALIDATE EMAIL ADDRESS
func isValidEmail(testStr:String) -> Bool {
  // println("validate calendar: \(testStr)")
  let emailRegEx = "[A-Z0-9a-z._%+-]+@[A-Za-z0-9.-]+\\.[A-Za-z]{2,4}"
  let emailTest = NSPredicate(format:"SELF MATCHES %@", emailRegEx)
  return emailTest.evaluateWithObject(testStr)
}
It still accepts false emails so long as it has the at "@" symbol with a ".com"
How can i validate user email is accurate such as a@google.com, etc? ... 
 
    