Protect Your Business with DMARC: Why Email Security Matters Now More Than Ever

May 29, 2025
Terminal B
Cybersecurity, Microsoft Office

Key Points

DMARC (Domain-based Message Authentication, Reporting, and Conformance) is a critical tool for protecting your business emails from spoofing and phishing attacks.
It ensures emails reach their intended recipients and helps meet compliance requirements like PCI DSS.
Microsoft’s new DMARC rules, effective May 5, 2026, require high-volume senders to authenticate emails, or risk having them sent to Junk or rejected.
Terminal B can set up and manage DMARC, saving you time and ensuring your emails are secure.

Imagine this: a customer receives an email that looks like it’s from your business, asking for sensitive information. They respond, only to discover it was a scam that cost them thousands. Or worse, your legitimate emails start landing in spam folders, causing missed invoices and frustrated clients. These are real risks in today’s digital world, but there’s a powerful solution: DMARC. This guide explains what DMARC is, why it’s essential for your business, and how Terminal B can help you stay secure—especially with Microsoft’s new email rules that started May 5, 2025.

What is DMARC and Why Should You Care?

DMARC stands for Domain-based Message Authentication, Reporting, and Conformance. It’s like a security guard for your email domain, ensuring only authorized senders can use it. DMARC works with two other protocols: SPF (Sender Policy Framework), which lists authorized email servers, and DKIM (DomainKeys Identified Mail), which adds a digital signature to verify emails. If an email fails these checks, DMARC tells the recipient’s server to monitor, quarantine, or reject it.

Without DMARC, your business is vulnerable to phishing attacks, where hackers impersonate you to steal data or money. It also risks deliverability issues, where your emails are flagged as spam, disrupting communication. Plus, industries like retail or healthcare face strict compliance rules, such as PCI DSS, that require robust email security.

The Real Cost of Skipping DMARC

Not having DMARC can hit your business hard. According to Osterman Research, a single phishing email costs an average of $31.32 and takes an average of 27.5 minutes to resolve.

For a small business, dozens of these incidents can add up to thousands in losses and hours of frustration.

Here’s a real-world example: a small accounting firm didn’t have DMARC, and a spoofed email tricked a client into wiring $10,000 to a fraudster. The client was furious, and the firm’s reputation took a hit.

Deliverability is another concern. Without DMARC, your emails might be marked as spam or blocked, meaning invoices, proposals, or customer updates never reach their destination. This can lead to delayed payments or lost opportunities. For instance, a retailer missed a critical holiday campaign because their emails were filtered out, costing them significant sales.

Microsoft’s New Rules: Act Now

On May 5, 2026, Microsoft rolled out stricter DMARC requirements for high-volume senders (those sending over 5,000 emails daily to Outlook.com, Hotmail.com, or Live.com). If your emails lack proper SPF, DKIM, and DMARC settings, they’ll be sent to the Junk folder—or eventually rejected entirely. This follows similar moves by Google and Yahoo, signaling a global push for better email security. For businesses relying on email marketing or client communication, compliance is critical to avoid disruptions. Learn more about Microsoft’s policy.

How DMARC Benefits Your Business

Implementing DMARC delivers immediate and long-term advantages:

Stop Spoofing: DMARC ensures only authorized senders use your domain, protecting your brand from phishing scams. This builds trust with customers and partners.
Boost Deliverability: A strong DMARC policy improves your domain’s reputation, ensuring emails land in inboxes, not spam folders. This means better communication and fewer missed opportunities.
Stay Compliant: DMARC aligns with regulations like PCI DSS, HIPAA, helping you stay ahead of your competitors.
Save Time and Money: By reducing phishing incidents, DMARC cuts the time and cost of resolving security breaches, letting you focus on growing your business.

For example, a local medical practice implemented DMARC with Terminal B’s help. Within weeks, they saw fewer phishing attempts, and their appointment reminders reached patients reliably, improving satisfaction and reducing no-shows.

How Your MSP Makes DMARC Easy

Setting up DMARC might sound technical, but Terminal B makes it seamless. They’ll:

Assess Your Setup: Review your current email configuration to identify gaps.
Implement DMARC: Configure SPF, DKIM, and DMARC policies tailored to your needs.
Monitor and Optimize: Use tools to track DMARC performance and adjust settings to maintain security.
Ensure Compliance: Keep yourself aligned with regulations like PCI DSS and Microsoft’s rules.

By partnering with Terminal B, you get peace of mind without the hassle. They handle the tech, so you can focus on running your business. Plus, they can provide ongoing support to keep your email security updated as threats evolve.

Why Act Now?

Cybercriminals don’t wait, and neither should you. With Microsoft’s new rules in effect and compliance deadlines looming, DMARC is no longer optional—it’s a must-have for any business using email. Delaying could mean costly phishing attacks, undelivered emails, or regulatory fines. By acting now, you protect your reputation, streamline communication, and show customers you take security seriously.

Take the Next Step with Your MSP

Don’t let email vulnerabilities hold your business back. Contact your Terminal B today to discuss DMARC and take control of your email security. They’ll guide you through the process, answer your questions, and set you up for success. Whether you’re a small business or a growing enterprise, DMARC is a simple step that delivers big results.

Schedule a free consultation now and safeguard your business for the future!