'Initialize the sensor.'

def __init__(self, hass, email_reader, name, allowed_senders, value_template):

    self.hass = hass
    self._email_reader = email_reader
    self._name = name
    self._allowed_senders = [sender.upper() for sender in allowed_senders]
    self._value_template = value_template
    self._last_id = None
    self._message = None
    self._state_attributes = None
    self.connected = self._email_reader.connect()
