Nope, Adobe has tools to make it easier but you do not have to use their tools. Typically for submitting a PDF you only need a program on the server side (a servlet, an ASP page, a Pearl script or simething like that) to recieve the transmission and then do something with what was sent in. If you decide to email the form in then you will need to Reader Extend the form to allow Reader users to do a local save. If you simply submit the form you will not have to Reader Extend it.
Make sure that you test the form inside and outside of the browser (served up from the server and saved on the local hard drive). Different HTML engines are used for submitting and you want to make sure that everything works the same for you in both environments (especially the message that you return that indicates that the submission has been recieved).
Hope that helps
Paul