From May 5, 2025, Microsoft mandates that all organizations sending 5 000 or more emails per day to its consumer services must implement DMARC, SPF, and DKIM to authenticate messages.
Senders must publish a DMARC record with at least a p=none policy and ensure alignment between DMARC and either SPF or DKIM. Non-compliance can result in messages being rejected or filtered into Spam folders.
Check out our guide on the Microsoft DMARC requirements to learn more.
To comply with the Microsoft DMARC requirements, senders must implement:
A DMARC record, with a minimum policy of p=none, must be published for the domain. This tells email receivers how to handle messages that fail SPF or DKIM checks. DMARC must be aligned with either SPF or DKIM, preferably both.
All outbound emails must pass SPF checks. SPF verifies that an email server is authorized to send messages on behalf of the domain.
All outbound messages must pass DKIM checks. DKIM applies a digital signature to verify the message's integrity and authenticity.
Microsoft enforces DMARC, SPF, and DKIM for emails sent to its users, and it provides aggregate reporting for domains whose MX record points to Microsoft infrastructure. But this visibility is limited to Microsoft’s own environment. For full DMARC compliance, domain owners need more than enforcement on a single platform.
That is where Sendmarc complements Microsoft. The Sendmarc platform gathers DMARC reports from thousands of receivers worldwide, not just Microsoft, and enriches them with insights that are easy to interpret and act on. We also help configure SPF, DKIM, and DMARC correctly across all your sending services, preventing legitimate emails from being rejected.
Together, Microsoft and Sendmarc provide complete protection. Microsoft secures your email within its ecosystem, while Sendmarc ensures your domain is fully compliant and protected everywhere your email travels.
Any business sending 5 000 or more messages daily to Microsoft email accounts must meet these requirements.
This includes:
Failure to comply may result in:
Sendmarc makes DMARC compliance easy, providing the tools needed to meet evolving requirements.
Book a demo or explore our platform to find out how we simplify DMARC adoption.
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“Microsoft’s update is a strong signal that the email ecosystem is maturing. These new requirements aren’t just about compliance—they’re about customer trust. High-volume senders need to step up and treat deliverability and authentication as core parts of their digital brand strategy, not just IT hygiene.”
– Nicolas Blank, Microsoft 365/Entra MVP and Founder of NBConsult
“While Microsoft’s new requirements apply to bulk senders, I believe every domain should have SPF, DKIM, and DMARC in place. These aren’t just technical best practices—they’re essential for protecting deliverability and reputation. Microsoft themselves say it best: ‘All senders benefit from these practices.’ It’s time the industry starts moving in that direction.”
– J. Peter Bruzzese, Microsoft MVP and Co-Founder of ClipTraining
If your business doesn’t implement DMARC for its domain, Microsoft might reject its emails. This could result in reduced deliverability and damage to your business’s sender reputation.