Hello bradley f1,
Thank you for reaching out to the Microsoft Community regarding your issue with sending emails using the Symfony framework. From the error message you provided, it seems like your application is facing authentication issues with the SMTP server, specifically Office365. This issue is not uncommon and can arise when the email service provider (in this case, Microsoft) makes security changes that impact how authentication works.
The error you're encountering, "Failed to authenticate on SMTP server using the following authenticators: LOGIN, XOAUTH2," along with the "535 5.7.139 Authentication unsuccessful" message, strongly indicates that Microsoft has disabled basic authentication for your account. As part of its ongoing efforts to improve security, Microsoft has been deprecating support for basic authentication (username/password) and moving towards modern authentication (OAuth2).
You mentioned that it was working previously and suddenly stopped, which aligns with Microsoft's timeline of gradually phasing out basic authentication across Office365 and Exchange services.
You've already made commendable efforts by:
- Setting up an app password, which is required when using basic authentication with two-factor authentication enabled.
- Using the correct port (587) and the correct server (smtp.office365.com).
- Attempting to troubleshoot using a valid app password.
Given that Microsoft has likely disabled basic authentication for your account, here are some potential solutions and workarounds:
Please refer to these Microsoft articles:
Authenticate an IMAP, POP or SMTP connection using OAuth | Microsoft Learn
Deprecation of Basic authentication in Exchange Online | Microsoft Learn
Enable Modern Authentication (OAuth2)
- Basic authentication is deprecated, so you'll need to migrate to modern authentication (OAuth2) for your email sending functionality. Symfony's Mailer component supports OAuth2, but you'll need to implement it using Microsoft's OAuth2 flow.
- Migrating to OAuth2 is crucial since Microsoft is phasing out basic authentication for security reasons. Below are the detailed steps to implement OAuth2 authentication in Symfony for sending emails via Office365.
You need to register your application with Azure AD to enable OAuth2 for your SMTP connection
- Go to the Azure Portal and sign in using your Microsoft account.
- Navigate to Azure Active Directory > App registrations.
- Click New registration.
- Name: Give your app a name (e.g., Symfony SMTP Mailer).
- Supported account types: Select the appropriate type based on whether your app will be used within your organization or more broadly.
- Redirect URI: Choose Public client/native (mobile & desktop) for now. You can change it later if needed.
- Click Register.
- After the registration, you’ll be taken to the app’s Overview page. Here, note down the Application (client) ID and Directory (tenant) ID. You’ll need these later.
Create Client Secret
- Navigate to Certificates & secrets.
- Under Client secrets, click New client secret.
- Give it a description (e.g., SMTP App Secret), and choose the expiration time.
- Click Add and note down the Client Secret Value. You won’t be able to view it again, so save it securely.
Grant SMTP Permissions
API Permissions
- Go to API permissions > Add a permission.
- Select Microsoft Graph > Delegated permissions.
- Search for
SMTP.Send and select it.
- After selecting, click Add permissions.
Admin Consent
- If required, click the Grant admin consent button to ensure the permissions are authorized by an admin in your organization.
Configure Symfony to Use OAuth2
To enable OAuth2 in Symfony’s Mailer component, you will use the client ID, secret, and tenant ID obtained earlier. Now we need to configure the Mailer service to send authenticated requests using OAuth2 tokens.
Install the Required Packages
First, ensure that you have the required Symfony Mailer packages installed.
bash
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composer require symfony/mailer symfony/google-mailer symfony/http-client
Install the OAuth2 Client Package
You’ll also need the league/oauth2-client package for OAuth2 support.
bash
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composer require league/oauth2-client
Create a Token Provider
Symfony’s Mailer component needs to fetch an OAuth2 token. You can create a service that does this for you.
Create a Token Provider service in your Symfony project:
php
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// src/Service/OutlookTokenProvider.php
namespace App\Service;
use Symfony\Component\HttpClient\HttpClient;
use Symfony\Contracts\HttpClient\HttpClientInterface;
use League\OAuth2\Client\Provider\GenericProvider;
use Symfony\Component\Mailer\Transport\Smtp\EsmtpTransport;
class OutlookTokenProvider
{
private $client;
private $tokenUrl;
private $clientId;
private $clientSecret;
private $tenantId;
public function __construct(string $clientId, string $clientSecret, string $tenantId)
{
$this->tokenUrl = "https://login.microsoftonline.com/$tenantId/oauth2/v2.0/token";
$this->clientId = $clientId;
$this->clientSecret = $clientSecret;
$this->tenantId = $tenantId;
$this->client = HttpClient::create();
}
public function getAccessToken(): string
{
$response = $this->client->request('POST', $this->tokenUrl, [
'body' => [
'client_id' => $this->clientId,
'client_secret' => $this->clientSecret,
'grant_type' => 'client_credentials',
'scope' => 'https://outlook.office365.com/.default',
]
]);
$data = $response->toArray();
return $data['access_token'];
}
}
Update your services.yaml file to include the token provider service.
yaml
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# config/services.yaml
services:
App\Service\OutlookTokenProvider:
arguments:
$clientId: '%env(OAUTH2_CLIENT_ID)%'
$clientSecret: '%env(OAUTH2_CLIENT_SECRET)%'
$tenantId: '%env(OAUTH2_TENANT_ID)%'
Configure the Mailer Transport
Now configure your Mailer to use this token provider. Symfony will use the token to authenticate against Office365's SMTP.
Update your Mailer configuration in .env:
dotenv
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# .env
OAUTH2_CLIENT_ID=<your_client_id>
OAUTH2_CLIENT_SECRET=<your_client_secret>
OAUTH2_TENANT_ID=<your_tenant_id>
MAILER_DSN=smtp://smtp.office365.com:587
Modify the Mailer Configuration to Use OAuth2
Update your Symfony Mailer transport to fetch and use OAuth2 tokens.
php
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// src/Service/MailerService.php
namespace App\Service;
use Symfony\Component\Mailer\MailerInterface;
use Symfony\Component\Mime\Email;
use App\Service\OutlookTokenProvider;
class MailerService
{
private $mailer;
private $tokenProvider;
public function __construct(MailerInterface $mailer, OutlookTokenProvider $tokenProvider)
{
$this->mailer = $mailer;
$this->tokenProvider = $tokenProvider;
}
public function sendEmail(string $to, string $subject, string $content)
{
$token = $this->tokenProvider->getAccessToken();
$transport = new EsmtpTransport('smtp.office365.com', 587);
$transport->setUsername('<your_username>@domain.com');
$transport->setPassword($token);
$this->mailer = new Mailer($transport);
$email = (new Email())
->from('<your_username>@domain.com')
->to($to)
->subject($subject)
->text($content);
$this->mailer->send($email);
}
}
Testing and Verifying
Clear Cache and Test
- Clear the cache using:bash
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php bin/console cache:clear
- Now, test sending an email with the updated OAuth2-based configuration.
- If your emails are still failing to send, review the logs in Symfony or your email provider to ensure OAuth2 tokens are being used correctly.
Use an App Password (With Basic Auth Enabled)
- If OAuth2 is not an immediate option, ensure that basic authentication is explicitly enabled for your Office365 account. Check with your Office365 administrator or through the Microsoft 365 Admin Center.
- If you have multi-factor authentication (MFA) enabled on your account, continue using an app-specific password for email authentication. However, this method will likely stop working eventually as Microsoft phases out basic authentication entirely.
Check SMTP Configuration
- Ensure that your SMTP server configurations in Symfony are correct:yaml
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MAILER_DSN=smtp://<USERNAME>:<APP_PASSWORD>@smtp.office365.com:587?encryption=tls
- Replace
<USERNAME> and <APP_PASSWORD> with the respective values. The app password must be the one generated in your account settings.
- Double-check any firewalls or network configurations that might block access to Office365's SMTP server.
Disable Security Defaults (if applicable):
- If your organization has security defaults enabled, it may be blocking basic authentication. While not recommended for security reasons, temporarily disabling these defaults may help you regain access.
- To disable security defaults, log into the Azure portal and navigate to Azure Active Directory > Properties > Manage Security Defaults.
Review Conditional Access Policies:
- Check if there are any conditional access policies that might be affecting your ability to authenticate via SMTP. These policies can restrict access based on various conditions.
Temporary Alternative: Use an External SMTP Provider
- As a workaround, you might consider using another SMTP provider, such as SendGrid or Mailgun, while you transition to OAuth2. These providers support modern authentication and are easily integrable with Symfony.
To resolve this issue permanently, migrating to OAuth2 authentication is recommended. If you need further assistance setting up OAuth2 with Symfony or have more questions, please don't hesitate to ask!
Please understand that our initial response may not always resolve the issue immediately. However, with your help and more detailed information, we can work together to find a solution.
Appreciate your patience and understanding and thank you for your time and cooperation. Have a great day!
Sincerely,
Microsoft Community Moderator
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