PHPMailer 在我使用 nginx 的 Digital Ocean 服务器上导致 504 超时错误

Question

我正在服务器上的一个 PHP 页面上安装电子邮件发送功能。我希望能够指定要发送的 gmail 帐户，所以我使用的是 PHPMailer。但是，每次我加载发送电子邮件的页面时，我都会在大约 30 秒后收到 504 网关超时错误。最终，电子邮件已发送(大约 5 分钟后我收到了)，但这正常吗？这是一封非常基本的文本电子邮件。

这是我发送邮件的代码

require '../html/lib/phpmailer/PHPMailerAutoload.php';


//Create a new PHPMailer instance
$mail = new PHPMailer;

//Tell PHPMailer to use SMTP
$mail->isSMTP();

//Enable SMTP debugging
// 0 = off (for production use)
// 1 = client messages
// 2 = client and server messages
$mail->SMTPDebug = 2;

//Ask for HTML-friendly debug output
$mail->Debugoutput = 'html';

//Set the hostname of the mail server
$mail->Host = 'smtp.gmail.com';

//Set the SMTP port number - 587 for authenticated TLS, a.k.a. RFC4409 SMTP submission
$mail->Port = 587;

//Set the encryption system to use - ssl (deprecated) or tls
$mail->SMTPSecure = 'tls';

//Whether to use SMTP authentication
$mail->SMTPAuth = true;

//Username to use for SMTP authentication - use full email address for gmail
$mail->Username = "user@gmail.com";

//Password to use for SMTP authentication
$mail->Password = "pw";

//Set who the message is to be sent from
$mail->setFrom('from@gmail.com', 'First Last');

//Set an alternative reply-to address
//$mail->addReplyTo('@example.com', 'First Last');

//Set who the message is to be sent to
$mail->addAddress('recip@gmail.com', 'recip');
$mail->Subject = 'PHPMailer GMail SMTP test 2';

//Read an HTML message body from an external file, convert referenced images to embedded,
//convert HTML into a basic plain-text alternative body
//$mail->msgHTML(file_get_contents('contents.html'), dirname(__FILE__));

//Replace the plain text body with one created manually
$mail->Body = 'This is another plain-text message body';

//Attach an image file
//$mail->addAttachment('images/phpmailer_mini.png');

//send the message, check for errors
if (!$mail->send()) {
    echo "Mailer Error: " . $mail->ErrorInfo;
} else {
    echo "Message sent!";
}

Answer 1

SMTP 超时时间很长(至少 5 分钟)。你得到的 504 是因为 nginx 和你的 PHP cgi(我假设你正在运行 FPM)之间的超时时间更短，所以当 PHP 产生错误时，nginx 已经断开了连接，所以你没有得到任何反馈。

这很可能是您主机上的 DNS 或防火墙问题 - 查看 the troubleshooting docs .