Cannot authenticate during send-mail process via PHP-Script(O365 SMTP) - MFA Problem

Question

Hi Guys,

i have a problem and dont know why this is not working for me..

I have a website on Azure(app-service/linux) and want to configure a send mail process via PHPmailer(php).
I tried to create my connection with this official Microsoft document --> Link <--- i tried it with Option 1.

This is my Code:

<?php
session_start();

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

// Load Composer's autoloader
require 'vendor/autoload.php';



return function ($site, $pages, $page)
{
	if(isset($_POST['submit']))
	{
		try {	

				// Instantiation and passing `true` enables exceptions
			$mail = new PHPMailer(true);

			//Server settings
			//$mail->SMTPDebug = SMTP::DEBUG_SERVER;
			$mail->SMTPDebug = 3;   			// Enable verbose debug output
			$mail->isSMTP();                                            // Send using SMTP
			$mail->Host       = 'smtp.office365.com';                    // Set the SMTP server to send through
			$mail->SMTPAuth   = true;                                   // Enable SMTP authentication
			$mail->Username   = '[e-mail]';                     // SMTP username
			$mail->Password   = 'PASSWORD';                               // SMTP password
			$mail->SMTPSecure = PHPMailer::ENCRYPTION_STARTTLS;
			//$mail->SMTPSecure = 'tls';			// Enable TLS encryption; `PHPMailer::ENCRYPTION_SMTPS` also accepted
			$mail->Port       = 587;                                    // TCP port to connect to

			//Recipients
			$mail->setFrom('[e-mail]', 'Mailer');
			$mail->addAddress('[e-mail]', 'Joe User');

			// Content
			$mail->isHTML(true);                                  // Set email format to HTML
			$mail->Subject = 'Here is the subject';
			$mail->Body    = 'This is the HTML message body <b>in bold!</b>';

			$mail->send();
		}catch (Exception $e) {
			echo "Message could not be sent. Mailer Error: {$mail->ErrorInfo}";
		}

		//header('Location: /kontakt');		
	}
};

The Error-Log on the Website:

2019-10-25 14:10:43 Connection: opening to smtp.office365.com:587, timeout=300, options=array()
2019-10-25 14:10:43 Connection: opened
2019-10-25 14:10:43 SERVER -> CLIENT: 220 AM3PR07CA0137.outlook.office365.com Microsoft ESMTP MAIL Service ready at Fri, 25 Oct 2019 14:10:42 +0000
2019-10-25 14:10:43 CLIENT -> SERVER: EHLO My-Homepage.de
2019-10-25 14:10:43 SERVER -> CLIENT: 250-AM3PR07CA0137.outlook.office365.com Hello [23.100.0.119]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-STARTTLS250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
2019-10-25 14:10:43 CLIENT -> SERVER: STARTTLS
2019-10-25 14:10:43 SERVER -> CLIENT: 220 2.0.0 SMTP server ready
2019-10-25 14:10:43 CLIENT -> SERVER: EHLO My-Homepage.de
2019-10-25 14:10:43 SERVER -> CLIENT: 250-AM3PR07CA0137.outlook.office365.com Hello [23.100.0.119]250-SIZE 157286400250-PIPELINING250-DSN250-ENHANCEDSTATUSCODES250-AUTH LOGIN XOAUTH2250-8BITMIME250-BINARYMIME250-CHUNKING250 SMTPUTF8
2019-10-25 14:10:43 CLIENT -> SERVER: AUTH LOGIN
2019-10-25 14:10:43 SERVER -> CLIENT: 334 VXNlcm5hbWU6
2019-10-25 14:10:43 CLIENT -> SERVER: <credentials hidden>
2019-10-25 14:10:43 SERVER -> CLIENT: 334 UGFzc3dvcmQ6
2019-10-25 14:10:43 CLIENT -> SERVER: <credentials hidden>
2019-10-25 14:10:49 SERVER -> CLIENT: 535 5.7.3 Authentication unsuccessful [AM3PR07CA0137.eurprd07.prod.outlook.com]
2019-10-25 14:10:49 SMTP ERROR: Password command failed: 535 5.7.3 Authentication unsuccessful [AM3PR07CA0137.eurprd07.prod.outlook.com]
SMTP Error: Could not authenticate.
2019-10-25 14:10:49 CLIENT -> SERVER: QUIT
2019-10-25 14:10:49 SERVER -> CLIENT: 221 2.0.0 Service closing transmission channel
2019-10-25 14:10:49 Connection: closed
SMTP Error: Could not authenticate.
Message could not be sent. Mailer Error: SMTP Error: Could not authenticate.

when i check the AzureAD Login-Logs i get this:

..

I thought it wouldn't matter if MFA is activated by the user or not?
Even when i exclude the User from the "MFA for Admins Policy", i get an error with the "End user protection".

What am i doing wrong?
I hope you can help me..

Thanks!

Leon

PS: if i selected the wrong forum then sorry.. you can move it to the right one.

Answer 1

Hey LonBoy98,

You will need to generate an app password and then use an app password for that account, instead of the regular user password. See here on how to do this: https://support.office.com/en-us/article/create-an-app-password-for-office-365-3e7c860f-bda4-4441-a618-b53953ee1183

This app password serves as the second authentication method for the dual authentication.   

Others have adopted a third party mailing system with complete DKIM/DMARC/SPF records in place for this third party sender. 

This eliminates the hassle of using an Office 365 SMTP account to send email.  

 Please remember to mark one of the responses as answer if your question has been answered. If not please let us know if there are anymore questions. Thanks

Answer 2

I will try this solution as soon as possible and mark it as correct answer if its works.

so thanks!

Leon