public function setMessageId($id = true)
    {
        if ($id === null || $id === false) {
            return $this;
        } elseif ($id === true) {
            $id = $this->createMessageId();
        }

        if ($this->_messageId === null) {
            $id = $this->_filterOther($id);
            $this->_messageId = $id;
            $this->_storeHeader('Message-Id', '<' . $this->_messageId . '>');
        } else {
            /**
             * @see Zend_Mail_Exception
             */
            // require_once 'Zend/Mail/Exception.php';
            throw new Zend_Mail_Exception('Message-ID set twice');
        }

        return $this;
    }
public function setMessageId($id = true)
    {
        if ($id === null || $id === false) {
            return $this;
        } elseif ($id === true) {
            $id = $this->createMessageId();
        }

        if ($this->_messageId === null) {
            $id = $this->_filterOther($id);
            $this->_messageId = $id;
            $this->_storeHeader('Message-Id', '<' . $this->_messageId . '>');
        } else {
            /**
             * @see Zend_Mail_Exception
             */
            // require_once 'Zend/Mail/Exception.php';
            throw new Zend_Mail_Exception('Message-ID set twice');
        }

        return $this;
    }
public function setMessageId ( $ id = true ) { if ( $ id === null || $ id === false ) { return $ this ; } elseif ( $ id === true ) { $ id = $ this -> createMessageId ( ) ; } if ( $ this -> _messageId === null ) { $ id = $ this -> _filterOther ( $ id ) ; $ this -> _messageId = $ id ; $ this -> _storeHeader ( 'Message-Id' , '<' . $ this -> _messageId . '>' ) ; } else { /**
             * @see Zend_Mail_Exception
             */ // require_once 'Zend/Mail/Exception.php'; throw new Zend_Mail_Exception ( 'Message-ID set twice' ) ; } return $ this ; }
Sets the Message-ID of the message

@param   boolean|string  $id
true  :Auto
false :No set
null  :No set
string:Sets given string (Angle brackets is not necessary)
@return  Zend_Mail Provides fluent interface
@throws  Zend_Mail_Exception
Sets the Message - ID of the message