How can I change the default RETURNTYPE?

You can change the default value for RETURNTYPE by logging into your account on http://hlrlookup.cardboardfish.com and clicking on Configuration. From the Default Return Type panel a new default can be set up, including an HTTP address or an e-mail address.

Please note that the web account option can only be used for HLR requests sent from the website. Requests sent using the HTTP interface should use either an HTTP address or an e-mail address.