3 Common Mistakes Companies Make with DMARC

Email spoofing and phishing attacks remain a major security issue, and DMARC is an essential tool to mitigate the threat. But for many organizations, DMARC is more of a theoretical shield than a practical defence. Thousands of companies are publishing a DMARC record, yet remain vulnerable to these attacks from easily addressed problems and misconfiguration. This leaves gaps and vulnerabilities in their email protection.

It is fairly common for companies to develop DMARC to solve the email spoofing problem; in reality, it creates either a reporting and collection mechanism or, in worst-case scenarios, even blocks legitimate messages. What they need is a practical method that steps through the common pitfalls of DMARC development.

Here are the three most frequent mistakes organizations make with DMARC and how to fix them. 

Mistake #1: Stopping at p=none 

The most common mistake in DMARC setups is the p=none policy and then never progressing. It is important to note that the primary “monitor-only” policy is intended to begin collecting visibility into your email ecosystem. But for many organizations, once the initial DMARC setup is completed, that is where the process ends. This leaves the domain completely vulnerable to being spoofed and impersonated.

The danger: 

When you use p=none, you are essentially instructing recipient mail servers not to do anything to unauthenticated emails. This means that any spoofed email leveraging your domain is still going to make it into the inbox. You are not preventing an attack; you are just gathering data. The result? Disruption to brand safety, loss of trust, and an invitation to phishing attacks.

The answer: 

Move away from p=none to an enforced policy over a phased implementation.

• Phase 1 (p=none): Monitor the reports, and declare all legitimate senders.
• Phase 2 (p=quarantine): Send mail that looks suspicious into spam folders to begin testing the enforcement.
• Phase 3 (p=reject): Block all unauthenticated mail once you are confident about the authentication.

How TDMARC can help

Threatcop’s TDMARC includes a guided policy migration engine that brings you along from monitoring to quarantine to the reject option. It’s intelligent DMARC monitoring, real-time dashboards, and threat detection (spoofed senders, blacklisted IPs, look-alike domains, etc.) give you confidence to move toward the complete enforceable option without guessing.

Mistake #2: Misconfigured SPF and DKIM records

DMARC doesn’t exist on its own; it is dependent on SPF and DKIM to operate. A common issue is misconfigured or incomplete records that cause DMARC to not work- even for legitimate emails.

The risk:

• If your SPF record exceeds the 10 DNS lookup limit, it can be completely disregarded. 
• If your DKIM keys aren’t aligned or the signing domain is incorrect, authentication breaks.
• Most third-party senders, including marketing, HR, and SaaS tools, go unnoticed.

In the end, not only legitimate emails need to be flagged or blocked, but bad deliverability will impact your business communications.

The solution:

• Audit all the platforms that send on behalf of your domain.
• Check that SPF records, DKIM keys, and the re-signing domain are not misaligned.
• Flatten the SPF record if necessary to stay within the lookup limits.

How TDMARC helps

TDMARC enables you to set up SPF, DKIM, and Smart DMARC and manage all three in one place. After setup, TDMARC automatically helps avoid the 10-lookup SPF limit, verifies DKIM alignment, and manages BIMI records to enhance brand trust within the inbox. IAM, SSO, and multi-domain admin controls give enterprises the chance to centrally manage authentication for all business units. 

Mistake #3: Ignoring or Misreading DMARC Reports

DMARC provides aggregate (RUA) reports, which are equivalent to the eyes and ears of your email security system. But the reports come as raw XML files. Most teams either throw these reports away or let them pile up unattended in a mailbox unread.

The risk: 

Disregarding reports is like putting in a security camera and never watching the capture. Spoofing, unintended misconfigurations of senders, and unauthorized use of domains can slip through the cracks, which makes enforcement impossible.

The solution: 

Leverage a reporting tool that can make sense of manageable XML to create actionable intelligence. Ensure that your DMARC record has a rua tag and point reports into a capable mailbox.

How TDMARC Helps

TDMARC takes unreadable XML files and compiles them into actionable dashboards so you can see:

• Authentication pass/fail rates
• Geolocations of senders and IP Reputation
• Volume of traffic over time
• Spoofed or unauthorized sources

With granular analytics, custom alerts, and real-time threat detection, your team can see the end-to-end picture and respond to threats faster, instead of drowning in raw data.

The Cost of These DMARC Mistakes

All of these mistakes come with serious consequences, such as financially, reputation, and regulatory compliance. 

• Damage to brand: Spoofed emails undermine customer confidence and reduce the effectiveness of legitimate campaigns.
• Increased phishing exposure: Employees, partners, and customers become victims of fraud and credential theft.
• Deliverability problems: Legitimate mail is blocked or filtered affecting vital business communications.
• Compliance exposure: Regulators now, more than ever, expect organizations to demonstrate mature email authentication processes, and when they don’t, organizations may be liable for fines.

Consider this: a single successful phishing campaign launched from a spoofed domain can cost millions in lost revenue, legal fees, and long-term reputation repair. Fixing a DMARC configuration issue costs far less than fixing the fallout of a breach.

Don’t Let Your DMARC Underperform

DMARC works, but it must be implemented correctly. Organizations risk exposure when DMARC is set to p=none, SPF/DKIM is misconfigured, or reports are ignored. These are three of the most common DMARC misconfigurations, and all are completely preventable. 

And the good news? Companies don’t have to deal with the complexity of DMARC by themselves. That’s where TDMARC by Threatcop comes in! TDMARC protects over 3,100 domains with greater than 95% compliance, combining:

• SPF, DKIM, and Smart DMARC setup and monitoring
• BIMI management for inbox trust and visibility
• Real-time threat detection (lookalike domains, spoofed senders, blacklisted IPs)
• Granular reporting based on geolocation, sender, receiver, and compliance 
• Enterprise-ready IAM, SSO, and multi-domain admin controls