Controller/Payment/AbstractAction.php
protected function assignGuestEmail(Quote $quote, $email) {
        $quote->setCustomerEmail($email);
        $quote->getCustomer()->setEmail($email);
        $quote->getBillingAddress()->setEmail($email);
    }
protected function assignGuestEmail(Quote $quote, $email) {
        $quote->setCustomerEmail($email);
        $quote->getCustomer()->setEmail($email);
        $quote->getBillingAddress()->setEmail($email);
    }
protected function assignGuestEmail ( Quote $ quote , $ email ) { $ quote -> setCustomerEmail ( $ email ) ; $ quote -> getCustomer ( ) -> setEmail ( $ email ) ; $ quote -> getBillingAddress ( ) -> setEmail ( $ email ) ; }
Assigns the given email to the provided quote instance.

@param Quote $quote
@param $email
Assigns the given email to the provided quote instance .