Given an email address, checks the local
    cache if corresponding email address: channel_id
    mapping exists

    email
        Email escalation policy
    profile
        A dict of telemetry config information.

def _retrieve_channel_id(email, profile='telemetry'):
    '''
    Given an email address, checks the local
    cache if corresponding email address: channel_id
    mapping exists

    email
        Email escalation policy
    profile
        A dict of telemetry config information.
    '''
    key = "telemetry.channels"
    auth = _auth(profile=profile)

    if key not in __context__:
        get_url = _get_telemetry_base(profile) + "/notification-channels?_type=EmailNotificationChannel"
        response = requests.get(get_url, headers=auth)

        if response.status_code == 200:
            cache_result = {}
            for index, alert in enumerate(response.json()):
                cache_result[alert.get('email')] = alert.get('_id', 'false')

            __context__[key] = cache_result

    return __context__[key].get(email, False)