mail()-question

Hi! I want PHP to do the following: send a mail to an address, given by a surfer via a from with the mail()-function - well this works fine! But what about misspelled email-addresses?? I tried it, with: mail($sendto, $subject, $message, "From: wrong_emails_here@mysite.com"); and gave an incorrect emailaddress in $sendto. I expected the email in the mailbox of "wrong_emails_here@mysite.com", but it never arrived!!! What can I try else, to get the mails, that coudn't be delivered into "wrong_emails_here@mysite.com"? thanks for any help michi -- Sent through GMX FreeMail - http://www.gmx.net