In some ways the "from" doesn't matter much, it's just where the email will say it's been sent from.
I recently had a client who had a webhost where the form didn't work. I had to set up an email account on the webhost before the webhost would enable outgoing mail. Maybe that's the problem?
If you are trying to test the form in preview mode, it won't work.
Do you get a message that the form has posted correctly?