Simple form submitted notification

Submitting the form with email - which isn't very safe or reliable - will need the user to make extra clicks. So they should be aware that they have done this, and whether it suceeded or failed or they cancelled or gave up or left it for later. So it may be counter productive to pop up a message saying "the form was submitted". The user may assume that good things have happened, and give up on the potentially complicated and confusing business of making the form submit, looking up their email passwords and whatever. (Much safer to submit to https. mailto is not really suitable for serious or business use, it's just a toy for testing, or occasionally use in strictly regimented corporate settings).

That depends on how the form is submitted. If by email, then no, because you can't know if it went through or not. If it's submitted to a web-service then yes, as that service can return an FDF string to the file and that will be parsed by it and displayed. It can include an alert window, or make a field visible, etc.