You haven't done anything to verify that mail has been queued. This suppresses any errors from mail, and then simply tells you it was successful. Change mail to detect if a queue was performed:
if (!mail($email_to, $email_subject, $email_message, $headers))
// do something to indicate a queue failure.
Still won't guarantee anything, but so long as that pulls up successful the problem isn't with PHP.
Originally Posted by ahaberman25
I have used this script before and it has worked until now for some reason.
This indicates something else has changed. Check your error logs for both sendmail and PHP.