Chances are you already have a powerful form handler. If you have a recent version of MODx have a look in assets/snippets/eform/. (otherwise you can download it here) Documentation for eForm can be found in /assets/snippets/eform/docs/eform.htm.
eForm by default sends form result to an email address of your choice, but through it’s ’events’ you can extend it to handle the results differently. Have a look through the examples in the documentation or browse through eForm’s support forum
