Creating a form is not sufficient you must either:
1. Use a third party provider such as Bravenet
2. Download a pre-written PHP email programme
3. Hand code your own PHP programme.
Options 1 and 2 will come with instructions, if you have to ask here then don't even think about option 3.
Third party providers normally use the address that you register with. Some email services such as Yahoo and Hotmail may treat the messages as spam.