邮件进入垃圾邮件文件夹(php邮件功能） - Mail goes to spam folder ( php mail function )

这段代码是我用来发送邮件的，但不幸的是，邮件进入了垃圾邮件文件夹。我尝试了gmail和hotmail，但情况是一样的。php代码为：

<?php
if($_POST)
{
//check if its an ajax request, exit if not
if(!isset($_SERVER['HTTP_X_REQUESTED_WITH']) AND strtolower($_SERVER['HTTP_X_REQUESTED_WITH']) != 'xmlhttprequest') {
    die();
} 
$to_Email       = "zinan09@gmail.com"; //Replace with recipient email address
$subject        = 'My email from Somebody out there...'; //Subject line for emails
//check $_POST vars are set, exit if any missing
if(!isset($_POST["userName"]) || !isset($_POST["userEmail"]) || !isset($_POST["userMessage"]))
{
    die();
}
//Sanitize input data using PHP filter_var().
$user_Name        = filter_var($_POST["userName"], FILTER_SANITIZE_STRING);
$user_Email       = filter_var($_POST["userEmail"], FILTER_SANITIZE_EMAIL);
$user_Message     = filter_var($_POST["userMessage"], FILTER_SANITIZE_STRING);
//additional php validation
if(strlen($user_Name)<4) // If length is less than 4 it will throw an HTTP error.
{
    header('HTTP/1.1 500 Name is too short or empty!');
    exit();
}
if(!filter_var($user_Email, FILTER_VALIDATE_EMAIL)) //email validation
{
    header('HTTP/1.1 500 Please enter a valid email!');
    exit();
}
if(strlen($user_Message)<5) //check emtpy message
{
    header('HTTP/1.1 500 Too short message! Please enter something.');
    exit();
}
//proceed with PHP email.
$headers = 'From: '.$user_Email.'';
@$sentMail = mail($to_Email, $subject, $user_Message .'  -'.$user_Name, $headers);
if(!$sentMail)
{
    header('HTTP/1.1 500 Could not send mail! Sorry..');
    exit();
}else{
    echo 'Hi '.$user_Name .', Thank you for your email! ';
    echo 'Your email has already arrived in my Inbox, all I need to do is Check it.';
}
}
?>

是否有任何缺失的函数需要添加或修改以解决此问题

尝试将From标头设置为实际的服务器域地址（即。no-reply@mysite.com)，并将用户电子邮件移动到Reply-To标头。这将使反垃圾邮件过滤器平静下来。

$headers = 'From: no-reply@mysite.com' . "'r'n";
$headers .= 'Reply-To: '.$user_Email.'';

正如我在评论中所说，您可能需要查看您的内容。

此外，您的电子邮件发件人与电子邮件收件人相同。我会修改它，使其成为一封你无法回复的静态电子邮件。

此外，你的邮件有5个变量，不知道为什么，但如果你使用标题，你可以把它们放在那里。

例如。

    $message = wordwrap($message, 70);  
    $to = "info@somewebsite.com";  // change this propperty for your own email
    $subject = "Een gebruiker heeft een vraag of opmerking";
    $body = 'yadidyadi'. $message ;
    $headers = "MIME-Version: 1.0" . "'r'n";
    $headers .= "Content-type:text/html;charset=UTF-8" . "'r'n";
    $headers .= "From: noreply@jellyfishwebdesign.nl"; // make this one static.. i made mine noreply
    if (mail ($to, $subject, $body, $headers)) {
       echo 'yay, mail send';
    }

编辑

只是要指出，这与你的问题无关，你的第一次检查，if($_POST)有点不相关，因为你想检查是否按下了某个按钮。如果你在这个文件中为不同的进程放入不同的代码，那么不管你是在编辑一篇文章，还是在数据库中输入一些东西，整个邮件都会被触发。。。将调用此文件的任何内容。