def METHOD_NAME(msg):
    """Saves an incoming message.  msg=string.  Message "To" field is expected to
    be in the format ietf-ipr+[identifier]@ietf.org.  Expect to find a message with
    a matching value in the reply_to field, associated to an IPR disclosure through
    IprEvent.  Create a Message object for the incoming message and associate it to
    the original message via new IprEvent"""
    message = message_from_bytes(force_bytes(msg))
    to = message.get('To', '')
    # exit if this isn't a response we're interested in (with plus addressing)
    local,domain = get_base_ipr_request_address().split('@')
    if not re.match(r'^{}\+[a-zA-Z0-9_\-]{}@{}'.format(local,'{16}',domain),to):
        return None
    try:
        to_message = Message.objects.get(reply_to=to)
    except Message.DoesNotExist:
        log('Error finding matching message ({})'.format(to))
        return None
    try:
        disclosure = to_message.msgevents.first().disclosure
    except:
        log('Error processing message ({})'.format(to))
        return None
    ietf_message = message_from_message(message)
    IprEvent.objects.create(
        type_id = 'msgin',
        by = Person.objects.get(name="(System)"),
        disclosure = disclosure,
        message = ietf_message,
        in_reply_to = to_message
    )
    log("Received IPR email from %s" % ietf_message.frm)
    return ietf_message