whats the difference in the bold part, and which one is correct send_email('info@domainname.com', $email, $topic, $body ); AND @ mail($email, $topic, $body, $headers); AND mail("info@domainname.com", $topic, $body, $from);
send_mail() is not a standard function, and it doesn't exist unless you define it. The @ operator silences possible error output. (Error messages) So all of them can be correct, if you define the first function yourself.