Starting May 5, Microsoft will require DMARC.

Check if your domain is compliant.

The Skysnag Blog

Guide to complying with Microsoft sender requirements to prevent 550 5.7.15 rejections. Ensure proper email authentication with SPF, DKIM, and DMARC for improved deliverability
May 5, 2025

How to Fix Microsoft Email Rejection Error 550 5.7.515

Microsoft is rejecting emails with error 550 5.7.515 due to failed DMARC, SPF, or DKIM authentication. Ensure compliance, restore deliverability, and protect your domain across Outlook, Hotmail, and Live with automated email authentication.

Explore insights

Learn what causes Microsoft email rejections with error 550 5.7.515. Understand authentication failures and how to resolve issues with SPF, DKIM, and DMARC for successful email delivery.
May 1, 2025

Microsoft Email Rejections Explained: 550 5.7.515 Authentication Failures

"Understand why AI-powered phishing attacks increase the need for strong email security. Discover how advanced threats bypass traditional filters and how authentication protocols like DMARC protect your domain."
April 30, 2025

Why AI-Powered Phishing Emails Make Strong Email Security Essential

Microsoft introduces new email sender requirements for Outlook. Ensure SPF, DKIM, and DMARC compliance by May 2025 to maintain deliverability and protect against spoofing and phishing threats.
April 3, 2025

Microsoft’s New Email Sender Requirements: What You Need to Know

UAE successfully blocks over 600 cyberattacks aimed at critical public and private sectors. Learn how national cybersecurity strategies are protecting vital infrastructure and sensitive data from evolving digital threats.
March 24, 2025

UAE blocks over 600 cyberattacks targeting critical sectors

Discover how to comply with the PCI DSS v4.0 2025 anti-phishing mandate using Skysnag. Learn key email security strategies, DMARC enforcement, and phishing protection best practices to safeguard payment data
March 11, 2025

PCI DSS v4.0.1 Countdown: How to Meet the 2025 Anti-Phishing Mandate with Skysnag

March 6, 2025

Upcoming NCSC Mail Check Changes and the Best Alternative

December 11, 2024

Deliverability vs. Security: Why Both Matter in Email Success

November 28, 2024

Stay Secure This Cyber Week: The Rise of Phishing Attacks

October 28, 2024

Google Expands BIMI Support Globally: Why This Matters for Your Brand

October 20, 2024

15 Myths Debunked: Google & Yahoo Email Sender Requirements

"Discover the differences between spear-phishing and whaling attacks, and learn how DMARC combined with Skysnag can safeguard your organization from email fraud by enhancing domain security and email authentication."
September 13, 2024

Whaling vs. Spear Phishing Explained

"Learn about the FBI's latest alert regarding North Korean phishing attacks aimed at businesses and government agencies. Understand the tactics used and how to strengthen cybersecurity measures against these growing threats."
September 4, 2024

FBI Alert: North Korea Attacks Cryptocurrency

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