为我解决这个问题的是，一些提供商在使用php邮件时不允许外部收件人:

将代码中的收件人($收件人)更改为本地收件人。这意味着使用来自服务器域的电子邮件地址，例如，如果您的服务器域是www.yourdomain.com，那么收件人的电子邮件地址应该是someone@yourdomain.com。 请上传修改后的php文件，然后重试。 如果仍然不工作:将发件人($sender)更改为本地电子邮件(使用与收件人相同的电子邮件)。 请上传修改后的php文件，然后重试。

希望这能有所帮助! https://www.arclab.com/en/kb/php/how-to-test-and-fix-php-mail-function.html

我觉得这个应该能搞定。我只是添加了一个if(isset，并在主体中的变量中添加了连接，以将PHP与HTML分开。

<?php
    $name = $_POST['name'];
    $email = $_POST['email'];
    $message = $_POST['message'];
    $from = 'From: yoursite.com'; 
    $to = 'contact@yoursite.com'; 
    $subject = 'Customer Inquiry';
    $body = "From:" .$name."\r\n E-Mail:" .$email."\r\n Message:\r\n" .$message;

if (isset($_POST['submit'])) 
{
    if (mail ($to, $subject, $body, $from)) 
    { 
        echo '<p>Your message has been sent!</p>';
    } 
    else 
    { 
        echo '<p>Something went wrong, go back and try again!</p>'; 
    }
}

?>

你可以使用PHPMailer，它工作得很完美，这里有一个代码示例:

<?php
use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

require 'vendor/phpmailer/phpmailer/src/Exception.php';
require 'vendor/phpmailer/phpmailer/src/PHPMailer.php';
require 'vendor/phpmailer/phpmailer/src/SMTP.php';
$editor = $_POST["editor"];
$subject = $_POST["subject"];
$to = $_POST["to"];

try {

    if ($_SERVER["REQUEST_METHOD"] == "POST") {

        $mail = new PHPMailer();
        $mail->IsSMTP();
        $mail->Mailer = "smtp";
        $mail->SMTPDebug  = 1;
        $mail->SMTPAuth   = TRUE;
        $mail->SMTPSecure = "tls";
        $mail->Port       = 587;
        $mail->Host       = "smtp.gmail.com";//using smtp server
        $mail->Username   = "XXXXXXXXXX@gmail.com";//the email which will send the email 
        $mail->Password   = "XXXXXXXXXX";//the password

        $mail->IsHTML(true);
        $mail->AddAddress($to, "recipient-name");
        $mail->SetFrom("XXXXXXXXXX@gmail.com", "from-name");
        $mail->AddReplyTo("XXXXXXXXXX@gmail.com", "reply-to-name");
        $mail->Subject = $subject;
        $mail->MsgHTML($editor);




        if (!$mail->Send()) {
            echo "Error while sending Email.";
            var_dump($mail);
        } else {
            echo "Email sent successfully";
        }
    }
} catch (Exception $e) {
    echo $e->getMessage();
}

把这两件事分开和一起尝试:

删除if($_POST['submit']){} 移除$from(只是我的直觉)

在邮件功能中添加邮件头。

$header = "From: noreply@example.com\r\n";
$header.= "MIME-Version: 1.0\r\n";
$header.= "Content-Type: text/html; charset=ISO-8859-1\r\n";
$header.= "X-Priority: 1\r\n";

$status = mail($to, $subject, $message, $header);

if($status)
{
    echo '<p>Your mail has been sent!</p>';
} else {
    echo '<p>Something went wrong. Please try again!</p>';
}

试试这个

if ($_POST['submit']) {
    $success= mail($to, $subject, $body, $from);
    if($success)
    { 
        echo '
        <p>Your message has been sent!</p>
        ';
    } else { 
        echo '
        <p>Something went wrong, go back and try again!</p>
        '; 
    }
}