ok, solved.
The following code in red was missing in "functions.php".
(To compare 2 files,the original and the modified one, I use WINMERGE software which is very usefull to immediatly see differences).
function check_email($email) {
return (preg_match('/^[-!#$%&\'*+\\.\/0-9=?A-Z^_`{|}~]+@([-0-9A-Z]+\.)+([0-9A-Z]){2,4}$/i', $email)) ? 1 : 0;
}.
Ouch, now when I click to send the postcard, it tells me to enter the captcha code, okk I 'll try to install this.. (hey this is the neverending story)
