Unable to send PHPMailer through gmail account from IIS on local machine

Question

I'm running Windows 10 Pro with IIS hosting PHP 5.6.11. In the past, an older version of PHPMail worked perfectly for sending emails via gmail in this type of windows/IIS/PHP setup. At some point in the past it quit working. So now I'm using the very latest PHPMail library as of January 6, 2018. Here is my simple example taken mostly from this gmail example.

use PHPMailer\PHPMailer\PHPMailer;
use PHPMailer\PHPMailer\Exception;

require 'src/Exception.php';
require 'src/PHPMailer.php';
require 'src/SMTP.php';

$mail = new PHPMailer;
$mail->isSMTP(); 
$mail->SMTPDebug = 2;
$mail->Host = "smtp.gmail.com";
$mail->Port = 587; // TLS only
$mail->SMTPSecure = "tls"; // ssl is depracated
$mail->SMTPAuth = true;
$mail->Username = $smtpUsername;
$mail->Password = $smtpPassword;
$mail->setFrom($emailFrom, $emailFromName);
$mail->addAddress($emailTo, $emailToName);
$mail->Subject = 'PHPMailer GMail SMTP test';
$mail->msgHTML("test body"); 
$mail->AltBody = 'HTML messaging not supported';

if(!$mail->send()){
    echo "Mailer Error: " . $mail->ErrorInfo;
}else{
    echo "Message sent!";
}

Here is the culprit:

Connection failed. Error #2: stream_socket_enable_crypto(): SSL operation failed with code 1. OpenSSL Error messages:error:14090086:SSL routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed [.....\PHPMailer\src\SMTP.php line 405]

How can I solve this?

UPDATE: I found the true source of the problem and updated the error message in this post, but I don't know how to solve it.

Answer 1

There are many case you have to check like

• open SSL in enable using you php ini
• you have to check your firewall that you are successfully able to access gmail server.
• etc you can find more solution and cases here

Answer 2

Change below value in your code.

$mail->Port = 587;
$mail->SMTPSecure = 'tls';
$mail->SMTPDebug = 2; //Get Error Details

Hope that's work.

Answer 3

I have tried everything that have been written on Stackoverflow but no luck. At last I omitted the line:

$mail->isSMTP();

Of course it is not a solution but in my case I had to solve the problem and it just did it. Now I'm using php's original mail() function. By the way I tried to use Gmail and Hotmail SMTP services. I don't want anyone to spend so much time on this like me.

Answer 4

Everything was solved when I installed a correct certificate in IIS.