The forums are here to help all those in need, but Daniel has a point - this specific question has been posed countless times, and a search would have revealed that. None the less, I hope you find this helpful:
In your form, do as follows:
Add a button (not the email submit button, just the "button").
Set the Control type to 'Submit' (under your Object tab).
On the Submit tab (under your Object tab), add "mailto:firstname.lastname@example.org" in the Submit to URL box.
Change the 'Submit As' drop down to 'PDF' (your other options are XML, XDP and FDF).
Save the form.