In the URL "http://wiki.uniformserver.com/index.php/PHP_mail_function" well written by "Ric", there is a problem. The php code of mail.php should be: " .../... // Retrieve the data form $email = $ _ POST ['email']; $subject = $ _ POST ['subject']; $message = $ _ POST ['message']; $headers = 'From: may.be@laposte.net."\ r \ n". <--(!) added line 'Reply-To: may.be@laposte.net."\ r \ n". 'X-Mailer: PHP /'.phpversion(); // Check if a $ _POST value exists // If not use defaults if (empty ($ _ POST ['email'])) { .../... " Indeed, without the php function @mail's parameter named $headers, many webmails respond with an smtp error. Here's an excerpt in the debug.log of fake sendmail for Windows: .../... DATA >> ipsum etc. <EOL> . <EOL> >> 550 5.5.0 Service refused, please try later. >> LPN105_510 <EOL> >> Disconnecting from smtp.laposte.net:25 Best regards.