def METHOD_NAME(list_name, msgid):
    # hash in mailarch is computed similar to
    # https://www.mail-archive.com/faq.html#listserver except the list
    # name (without "@ietf.org") is used instead of the full address,
    # and rightmost "=" signs are (optionally) stripped
    sha = hashlib.sha1(force_bytes(msgid))
    sha.update(force_bytes(list_name))
    return force_str(base64.urlsafe_b64encode(sha.digest()).rstrip(b"="))