problem with deleting records (with the record_type option)

[ezrubaal]

Hi,
I've been trying to delete MX records using this code line:

client.delete_records(domain, name='@', record_type='MX')

The long error message ends wtih:
godaddypy.client.BadResponse: Response Data: {'code': 'INVALID_RECORDS', 'fields': [{'code': 'INVALID_RECORDS', 'message': 'Invalid [ipaddress] provided for record data, [Parked].', 'path': 'records'}], 'message': 'One or more of the given records is invalid', 'errors': ['Invalid [ipaddress] provided for record data, [Parked].']}

I can't really see what I'm doing wrong, the code line is simple enough and all I did is to add the record_type='MX' which should work according to the documentation.

ALSO, I this line DOES work:
mx_records = client.get_records(domain, record_type='MX')
(which means that there's nothing wrong with "record_type='MX'")