While setting up an SMTP plugin with the Outlook mailer, you may encounter the error ‘invalid_request: AADSTS50194: Application is not configured as a multi-tenant application’. This error arises from your Azure settings.
Specifically, the application you’ve registered in Azure hasn’t been set up to support multiple tenants or personal Microsoft accounts.
Resolving the Error – Solution
To fix this issue, it’s essential to set the correct account type in your Azure portal during the registration process.
While going through the registration process, be sure to select the account type as Accounts in any organizational directory and personal Microsoft accounts.