Overview
The ‘invalid_request: AADSTS50194’ error often occurs on sites sending emails through Microsoft’s API. It indicates that the web application you set up in Azure is not doesn’t support personal accounts or multiple tenants.
When this happens, you’ll see an error message that reads: ‘Invalid_request: Application is not configured as a multi-tenant application’.
Causes
The main cause of this error is using an incorrect Azure web application configuration. When configuring your SMTP plugin to send emails through Microsoft’s API, you’ll need to set up a web application in the Azure portal.
If the application is not properly set up, you’ll likely encounter this error.
Solution
To resolve the ‘invalid_request: AADSTS50194’ error, you’ll need to update Azure application settings and choose the correct account type.
When setting up your web application, select the account type as “Accounts in any organizational directory and personal Microsoft accounts”.
Note: For more details, be sure to check our guide on setting up the Microsoft Outlook mailer in WP Mail SMTP.
That’s it! Now you know how to resolve the ‘invalid_request: AADSTS50194’ error.
Would you like to improve your site’s email deliverability? Consider configuring an additional connection to use as a backup mailer.