“After careful consideration and to ensure the protection of users and remove any confusion on why a message was in the junk folder for both the recipient and sender, we have made a decision to reject messages that don’t pass the required authentication requirements,” Microsoft stated in its official announcement. Security experts recommend using specialized DMARC analytical services to identify specific authentication issues, as traditional checkers may only verify if records exist without confirming actual compliance with Microsoft’s requirements. URI Ports advises in a recent blog post, “To diagnose and resolve the 550 5.7.15 error, we recommend testing your email authentication setup before the deadline. The rejected messages will specifically be designated as: “550 5.7.15 Access denied, sending domain [SendingDomain] does not meet the required authentication level”. Organizations dependent on email communications for marketing, notifications, or customer service should audit their authentication configurations immediately to avoid disruption when enforcement begins. The new policy specifically targets high-volume senders- organizations dispatching more than 5,000 emails daily to Microsoft’s consumer email services, including Outlook.com, Hotmail.com, and Live.com domains. Cyber Security News is a Dedicated News Platform For Cyber News, Cyber Attack News, Hacking News & Vulnerability Analysis. This enforcement, scheduled to take effect on May 5, 2025, represents a hardening of Microsoft’s initial approach, which had planned to route non-compliant messages to Junk folders. Kaaviya is a Security Editor and fellow reporter with Cyber Security News.
This Cyber News was published on cybersecuritynews.com. Publication date: Mon, 05 May 2025 06:00:03 +0000