无法通过我的PHP脚本建立与Gmail SMTP的连接

Question

我只想制作一个基本的电子邮件发送脚本。因为我想在本地主机上运行它，所以我使用Gmail SMTP。我都启用了IMAP设置，并且允许从不太安全的应用程序访问。令人惊讶的是，我仍然无法连接。每次尝试时，我都会收到错误SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

为什么会这样？我正在使用此代码：

   <?php

    use PHPMailer\PHPMailer\PHPMailer;

    if(isset($_POST['submit'])){
    $to = $_POST['email'];
    $subject = "First email";
    $txt = "Do you want our service?";


    //require_once('PHPMailer/PHPMailer.php');
    require_once "PHPMailer\PHPMailer.php";
    require_once "PHPMailer\SMTP.php";
    require_once "PHPMailer\Exception.php";


    $mail = new PHPMailer();
    $mail->isSMTP();
    $mail->SMTPAuth = true;
    $mail->SMTPSecure = "ssl";
    $mail->Host = "smtp.gmail.com";
    $mail->Port = 465;
    $mail->isHTML();
    $mail->Username = "myemailnotimportant@gmail.com";
    $mail->Password = "password123";
    $mail->SetFrom('myemailnotimportant@gmail.com', 'Sir Walter Scott');
    $mail->Subject = $subject;
    $mail->Body = $txt;
    $mail->AddAddress($to);


       if ($mail->Send()) {
       echo "email sent";
       } else {

           echo "Something is wrong: <br><br>" . $mail->ErrorInfo;

       }



    }
    ?>