如何使用PHP发送电子邮件

<?php
$message = "Line 1
Line 2
Line 3";
$message = wordwrap($message, 70, "
");
$retval=mail('xxx@gmail.com', 'My Subject', $message);
 if( $retval == true )
     {
        echo "Message sent successfully...";
     }else {
            echo "Message could not be sent...";
           }
?>

It gives me message as Message could not be sent .

Yor problem is here: $message = wordwrap($message, 70, " "); you neet to add .=

It is the same as $message = $message . "wordwrap($message, 70, " ")";