this script is great !
BUT (!!)
My mail server is protected by several systems.
If the form sent without email address or no good email address
the server is replying with an error that get to the senders eyes.

how can i avoid ugly errors like

"Warning: mail() [function.mail]: SMTP server response: 554 5.7.1 This message has been blocked because the return email domain is invalid.(failed to obtain DNS record for domain kdsfhlkdsfjl.cdcj) in C:\xampp\htdocs\liron2\formmail.php on line 419

Warning: Cannot modify header information - headers already sent by (output started at C:\xampp\htdocs\liron2\formmail.php:419) in C:\xampp\htdocs\liron2\formmail.php on line 195 "

from getting displayed to the surfer ???????? TNKS AVI