The spam is actually more likely to reach your inbox this way because form submissions will come from a certain address when sent to you (like mailer@example.com) which will seem less like spam to your filter. Also, since the subject line of the email won’t be touched by the spam bot, it will look more legit and you’ll be more likely to open it.

The form submission is not a good way to prevent spam, although it can be useful if you don’t want individuals (spammers and nonspammers alike) to know your address simply for privacy concerns, because email addresses can be used to identify you personally.

Why not just stick on a Disposable Email Address ?