DMARC, DKIM and SPF will be needed to keep your emails from the junk folder.
Microsoft is to enforce mandatory sender policy framework (SPF), DKIM and Domain-based Message Authentication, Reporting and Conformance (DMARC) standards on domains sending more than 5,000 daily emails from May.
In a statement, Microsoft said the measures “will help reduce spoofing, phishing, and spam activity, empowering legitimate senders with stronger brand protection and better deliverability.”
The company encouraged all senders, and particularly those that send at high volume, to review and update their SPF, DKIM, and DMARC records in preparation for when the enforcement begins.
“After May 5th 2025, Outlook will begin routing messages from high volume non‐compliant domains to the Junk folder, giving senders an opportunity to address any outstanding issues.” It also stated that non-compliant messages will be rejected to further protect users in the future.
Gerasim Hovhannisyan, CEO and Co-Founder of EasyDMARC, said: “Email providers stepping up to enforce stricter authentication is both necessary and logical. With Outlook used by millions of individuals and businesses worldwide, these measures can have a real impact on improving email security at scale.
“It's about staying competitive in security: Google and Yahoo began enforcing mandated email authentication for bulk senders a year ago, and the results show it's paying off. Microsoft’s decision helps make the entire email ecosystem safer, raising the bar for security across the board.”
Written by
Dan Raywood is a B2B journalist with 25 years of experience, including covering cybersecurity for the past 17 years. He has extensively covered topics from Advanced Persistent Threats and nation-state hackers to major data breaches and regulatory changes.
He has spoken at events including 44CON, Infosecurity Europe, RANT Forum, BSides Scotland, Steelcon and the National Cyber Security Show, and served as editor of SC Media UK, Infosecurity Magazine and IT Security Guru. He was also an analyst with 451 Research and a product marketing lead at Tenable.
