DMARC Authentication becomes Mandatory:

Email remains the backbone of business communication. It’s reliable, universal, and fast. But with its ease of use comes danger. Hornetsecurity’s annual research shows that email overwhelmingly remains the top vector for cyberattacks and that attackers are getting more sophisticated as AI allows them to reach more potential victims at scale.

From phishing and spoofing to business email compromise (BEC), cybercriminals are constantly trying to trick people into clicking on malicious links or divulging private data or their login details. The ways they try to trick people are not static, as the bad actors constantly tweak their tactics. One of the most common email attacks involves impersonating a trusted sender by ‘spoofing’ their domain. Stolen credentials, malware infections, damaged reputations, and significant financial loss are often the end results of any successful attacks.

How can organisations protect themselves and their users from domain-spoofing threats? The answer lies in email domain validation, specifically in DMARC. DMARC enables organisations to validate emails sent from their domains so that receiving email systems can check the authenticity of the senders.

The Current State of Email Security

Hornetsecurity inspects a lot of emails. And when we say a lot, in 2024, they analysed over 55 billion. Within these emails, more than a third were classified as “unwanted”, and 2.3% were categorised as actual threats. Phishing topped the list, making up a third of all email-based attacks, followed by malicious URLs and impersonation.

Social engineering remains at the heart of many of these email attacks. If an employee receives a convincing email that looks like it’s from their CEO or a trusted supplier, damage can often follow with just one click on a link that goes to a malicious website.

Many email systems, such as Microsoft 365, provide a solid protection foundation. However, it’s not immune to domain spoofing and other attack methods. Attackers often send convincing spoofed emails. It’s vital to protect your domains from impersonation and spoofing by attackers. That’s where DMARC shines.

What Is DMARC?

DMARC, short for Domain-based Message Authentication, Reporting & Conformance, is a protocol that helps organisations protect their email domains from spoofing. It works in conjunction with two other technologies:

• SPF (Sender Policy Framework) - Defines which mail servers are authorised to send emails on behalf of your domain.
• DKIM (DomainKeys Identified Mail) - Uses cryptographic signatures to verify the email’s integrity and authenticity.

DMARC allows domain owners to publish policies in DNS that tell receiving servers what to do if an email fails SPF or DKIM checks. For example, whether to accept the email, mark it as spam, or reject it entirely. Here’s a simplified outline of how DMARC operates:

1. Email arrives at the recipient’s server.
2. SPF and DKIM checks are run to see if the email is genuine. If it fails checks, your DMARC policy is applied.
3. DMARC policy options:
   • None - Email is accepted (used for monitoring only).
   • Quarantine - Email is marked as spam.
   • Reject - Email is blocked.

By configuring your DMARC policy to reject unauthorised emails, you effectively prevent cybercriminals from sending phishing emails that look like they came from your domain.

DMARC also provides reporting, giving organisations visibility into who sends emails using their domain — both authorised and unauthorised sources. This creates a powerful defence against domain spoofing and email impersonation attacks and also enables IT teams to spot misconfigurations, detect shadow IT, and monitor ongoing threats.

It’s worth pointing out that in February 2024, major email providers like Google made DMARC mandatory for organisations sending more than 5,000 messages a day. This requirement highlights how critical DMARC authentication has become. Not just for protection but also to make sure your emails get delivered in the first place. Failing to adopt DMARC could mean your intended recipients don’t get your emails!

DMARC Can Be Hard to Implement

While DMARC is powerful, it can also be technically complex to set up and manage, especially across multiple domains or when dealing with mail generated from automatic systems like CRMs and marketing platforms. This is where many organisations struggle. Without the right expertise, it’s easy to misconfigure SPF records, break email delivery, or leave gaps in protection. And maintaining the settings long-term as your IT environment evolves, is also a challenge.

Hornetsecurity DMARC Manager Email Authentication Simplified

Hornetsecurity DMARC Manager is a user-friendly, feature-rich platform that simplifies implementing and managing DMARC, even at scale. Deploying DMARC Manager makes it easy for organisations to take control of their email domain security. The key features of DMARC Manager are:

Domain Configurator - Easily set up and maintain DMARC, DKIM, and SPF best practice policies and TLS settings for multiple domains.

Status Dashboard - Get a comprehensive overview of managed domains, senders, sent emails, and emails that passed or failed DMARC.

Email Sources Analysis - Get a detailed overview of the sources sending emails via your domains.

BIMI Support - Display your logo beside emails in supported inboxes, maximising email impact, brand recognition and trust. BIMI stands for Brand Indicators for Message Identification. It’s an email standard that allows your logo to appear next to your emails in recipients’ inboxes if the email passes DMARC checks.

SMTP-TLS Reporting - Ensures outbound emails are encrypted and alerts you when delivery fails due to encryption issues.

Real-Time Alerts and Failure Reports - Stay informed with custom alerts when something suspicious happens, like a new unauthorised sender using your domain.

DMARC Report Aggregation - DMARC Manager can capture all reports sent by recipient servers back to the sender and then aggregate these into a single report.

Whether you manage a single domain or dozens, DMARC Manager gives you the tools to lock down your domains, reduce email spoofing, improve deliverability, and protect your brand identity and reputation via one console.

Watch the On-Demand Webinar

Hornetsecurity held a webinar in March 2025. The session is beneficial for MSPs looking to manage the DMARC settings for multiple clients. It covers what you need to know about SPF, DKIM, and DMARC, plus how the DMARC Manager can assist you in setting them up and monitoring them for client domains. We recommend this webinar for partners who have basic technical knowledge about email, domain management and the DNS zone.

It starts by looking at SPF, DKIM and DMARC, the three protocols that form the basis of anti-spoofing protection in email. After building a basic understanding of how they work, it shows how DMARC Manager can make implementing them for your domains or client domains much easier. Additionally, it looks at the various statistics the DMARC Manager provides to help you track what happens to sent emails and who is sending them from a domain.

View the webinar at: https://renaissance.renaissance.ie/c/440635/

Conclusion

Email spoofing, phishing, and brand impersonation are not going away. However, you can stay ahead of the threats with the help of Hornetsecurity’s DMARC Manager. It provides full visibility, control, and confidence about who uses a domain for email sending and who shouldn’t. It’s a crucial part of any organisation’s cybersecurity strategy.

Contact Renaissance today to learn more about Hornetsecurity’s DMARC Manager and arrange a demo or a consultation.