'Checks if the response code is "250". If strict is **True** then this
checks if the response is "250 OK"
:param bool strict: checks for a "250 OK" message if **True**
:returns:
* If strict is **False**: **True** if the response code is "250", **False** otherwise
* If strict is **True**: **True** if the response is "250 OK", **False** otherwise'

def is_ok(self, strict=False):

    if strict:
        return (self.content()[0] == ('250', '    ', 'OK'))
    return (self.content()[0][0] == '250')
