SMTP AUTH (Email Sending)

Question

I am told that App Passwords are expected to stop working by September 2025 for sending emails via SMTP AUTH. This is because they rely on "Basic Authentication," which Microsoft is permanently retiring for Exchange Online services.

Is this accurate and is there a work around to send from these devices from office365?

Answer 1

Yes, your information is accurate. Microsoft is deprecating Basic Authentication, which includes App Passwords for SMTP AUTH, and this change is expected to affect services by September 2025. As part of this transition, Microsoft encourages users to move to Modern Authentication (OAuth 2.0) for sending emails.

To send emails from devices that currently rely on SMTP AUTH, you should consider using one of the following alternatives:

1. Use OAuth 2.0: Implement OAuth 2.0 authentication for your applications that send emails. This is the recommended approach for secure email sending.
2. Use Microsoft Graph API: Instead of SMTP AUTH, you can use the Microsoft Graph API to send emails, which supports Modern Authentication.
3. Alternative SMTP services: If you have on-premises email servers, you may configure them to relay emails without relying on Basic Authentication.

It's important to start planning for this transition to ensure continued email functionality after Basic Authentication is fully retired.

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References:

• Deprecation of Basic authentication in Exchange Online
• How to set up a multifunction device or application to send email using Microsoft 365 or Office 365