Load the default identity from the configuration. If there is no default
    identity, a KeyError is raised.

def load_identity(config = Config()):
    """Load the default identity from the configuration. If there is no default
    identity, a KeyError is raised.
    
    """
    return Identity(name = config.get('user', 'name'),
                    email_ = config.get('user', 'email'),
                    **config.get_section('smtp'))