'Return a list of the basic fields for a single-part message.'

def _basicFields(self):

    headers = self.message.getHeaders(False, *self._HEADERS)
    size = self.message.getSize()
    (major, minor) = (self.main, self.subtype)
    unquotedAttrs = self._unquotedAttrs()
    return [major, minor, unquotedAttrs, headers.get('content-id'), headers.get('content-description'), headers.get('content-transfer-encoding'), size]
