Error with Email Class

[eluser]louis w[/eluser]
I am using the CI Email class with protocol = smtp and smtp_host set to the server address. No user or pass is set because the email server does not require it from my ip address.

I am getting this error:

502 Error: command not implemented

Seems like it is happening right after this:
$this->_send_data('.');
But if I comment that out it still errors.