def _sendPostDict(post_dict):
    """
    Send `post_dict` to the :attr:`.ALEPH_EXPORT_URL`.

    Args:
        post_dict (dict): dictionary from :class:`PostData.get_POST_data()`

    Returns:
        str: Reponse from webform.
    """
    downer = Downloader()
    downer.headers["Referer"] = settings.EDEPOSIT_EXPORT_REFERER
    data = downer.download(settings.ALEPH_EXPORT_URL, post=post_dict)
    rheaders = downer.response_headers

    error_msg = rheaders.get("aleph-info", "").lower().strip()
    if "aleph-info" in rheaders and error_msg.startswith("error"):
        raise ExportRejectedException(
            "Export request was rejected by import webform: %s" %
            rheaders["aleph-info"]
        )

    return data