public function setReturnPath($email)
    {
        if ($this->_returnPath === null) {
            $email = $this->_filterEmail($email);
            $this->_returnPath = $email;
            $this->_storeHeader('Return-Path', $email, false);
        } else {
            /**
             * @see Zend_Mail_Exception
             */
            // require_once 'Zend/Mail/Exception.php';
            throw new Zend_Mail_Exception('Return-Path Header set twice');
        }
        return $this;
    }
public function setReturnPath($email)
    {
        if ($this->_returnPath === null) {
            $email = $this->_filterEmail($email);
            $this->_returnPath = $email;
            $this->_storeHeader('Return-Path', $email, false);
        } else {
            /**
             * @see Zend_Mail_Exception
             */
            // require_once 'Zend/Mail/Exception.php';
            throw new Zend_Mail_Exception('Return-Path Header set twice');
        }
        return $this;
    }
public function setReturnPath ( $ email ) { if ( $ this -> _returnPath === null ) { $ email = $ this -> _filterEmail ( $ email ) ; $ this -> _returnPath = $ email ; $ this -> _storeHeader ( 'Return-Path' , $ email , false ) ; } else { /**
             * @see Zend_Mail_Exception
             */ // require_once 'Zend/Mail/Exception.php'; throw new Zend_Mail_Exception ( 'Return-Path Header set twice' ) ; } return $ this ; }
Sets the Return-Path header of the message

@param  string    $email
@return Zend_Mail Provides fluent interface
@throws Zend_Mail_Exception if set multiple times
Sets the Return - Path header of the message