@ali :- i didn't do this before , I was refer this code someone else. You just try it and if you got solution for this try to post as your answer.

def build_email(self, email_from, email_to, subject, body, email_cc=None, email_bcc=None, reply_to=False,
               attachments=None, message_id=None, references=None, object_id=False, subtype='plain', headers=None,
               body_alternative=None, subtype_alternative='plain'):
        email_from = email_from or tools.config.get('email_from')
        assert email_from, 
        headers = headers or {} # need valid dict later

        if not email_cc: email_cc = []
        if not email_bcc: email_bcc = []
        if not body: body = u''

        email_body_utf8 = ustr(body).encode('utf-8')
        email_text_part = MIMEText(email_body_utf8, _subtype=subtype, _charset='utf-8')
        msg = MIMEMultipart()

        if not message_id:
            if object_id:
                message_id = tools.generate_tracking_message_id(object_id)
            else:
                message_id = make_msgid()
        msg['Message-Id'] = encode_header(message_id)
        if references:
            msg['references'] = encode_header(references)
        msg['Subject'] = encode_header(subject)
        msg['From'] = encode_rfc2822_address_header(email_from)
        del msg['Reply-To']
        if reply_to:
            msg['Reply-To'] = encode_rfc2822_address_header(reply_to)
        else:
            msg['Reply-To'] = msg['From']
        msg['To'] = encode_rfc2822_address_header(COMMASPACE.join(email_to))
        if email_cc:
            msg['Cc'] = encode_rfc2822_address_header(COMMASPACE.join(email_cc))
        if email_bcc:
            msg['Bcc'] = encode_rfc2822_address_header(COMMASPACE.join(email_bcc))
        msg['Date'] = formatdate()
        # Custom headers may override normal headers or provide additional ones
        for key, value in headers.iteritems():
            msg[ustr(key).encode('utf-8')] = encode_header(value)

        if subtype == 'html' and not body_alternative and html2text:
            # Always provide alternative text body ourselves if possible.
            text_utf8 = tools.html2text(email_body_utf8.decode('utf-8')).encode('utf-8')
            alternative_part = MIMEMultipart(_subtype="alternative")
            alternative_part.attach(MIMEText(text_utf8, _charset='utf-8', _subtype='plain'))
            alternative_part.attach(email_text_part)
            msg.attach(alternative_part)
        elif body_alternative:
            # Include both alternatives, as specified, within a multipart/alternative part
            alternative_part = MIMEMultipart(_subtype="alternative")
            body_alternative_utf8 = ustr(body_alternative).encode('utf-8')
            alternative_body_part = MIMEText(body_alternative_utf8, _subtype=subtype_alternative, _charset='utf-8')
            alternative_part.attach(alternative_body_part)
            alternative_part.attach(email_text_part)
            msg.attach(alternative_part)
        else:
            msg.attach(email_text_part)

        if attachments:
            for (fname, fcontent) in attachments:
                filename_rfc2047 = encode_header_param(fname)
                part = MIMEBase('application', "octet-stream")

                # The default RFC2231 encoding of Message.add_header() works in Thunderbird but not GMail
                # so we fix it by using RFC2047 encoding for the filename instead.
                part.set_param('name', filename_rfc2047)
                part.add_header('Content-Disposition', 'attachment', filename=filename_rfc2047)

                part.set_payload(fcontent)
                Encoders.encode_base64(part)
                msg.attach(part)
        return msg  

thanks

Logicious