Many organisations assume that if they send an email, it will reach the recipient.

That’s no longer guaranteed.

Over the past two years, major email providers including Google, Yahoo, and Microsoft have tightened sender authentication rules to reduce spam, phishing, and impersonation attacks. These changes mean that organisations sending email must properly authenticate their domains using SPF, DKIM and DMARC.

When these controls are missing or misconfigured, messages may be:

• sent to junk folders

• delayed

• or rejected completely

For many organisations, the impact is subtle.

Sales emails go unanswered.
Customers say they never received an invoice.
Important messages disappear into spam folders.

The issue isn’t your email content.

It’s your domain reputation.

The deliverability problem most businesses don’t realise they have

Email providers use authentication signals to determine whether a sender can be trusted.

These signals include:

• SPF (Sender Policy Framework)

• DKIM (DomainKeys Identified Mail)

• DMARC (Domain-based Message Authentication, Reporting and Conformance)

When configured correctly, these controls prove that the email genuinely came from your organisation.

Without them, receiving systems have no reliable way to verify the sender.

The result is predictable.

Messages are treated with suspicion.

That suspicion often means your emails end up in junk folders instead of inboxes.

What DMARC actually does

DMARC sits on top of SPF and DKIM and provides two critical capabilities.

Domain protection

DMARC prevents attackers from impersonating your domain in phishing or invoice fraud attacks.

Without DMARC protection, criminals can send messages that appear to come from your organisation.

Visibility

DMARC also provides detailed reporting showing exactly who is sending email using your domain.

For many organisations this reveals something surprising.

There are often far more systems sending email than expected, including:

• Microsoft 365

• website contact forms

• CRM systems

• booking platforms

• finance tools sending invoices

• marketing platforms

Without DMARC reporting, these sending sources remain invisible.

“We don’t send thousands of emails – do we still need DMARC?”

This is a question we hear regularly from small businesses, schools and care providers.

The answer is yes.

While Google, Yahoo and Microsoft introduced stricter authentication rules for high-volume senders, DMARC is not just about marketing emails.

It’s about preventing attackers from impersonating your organisation.

Cyber criminals rarely need to send thousands of emails pretending to be you.

They only need to send one convincing message.

Examples include:

• a fake invoice sent to one of your customers

• an email pretending to be your finance team requesting payment

• a message impersonating a school or care provider asking for urgent information

Without DMARC protection, attackers can send emails that look like they came from your domain.

That damages trust in your organisation and increases the risk of fraud.

DMARC helps stop that by telling receiving email systems how to verify messages sent from your domain.

In other words:

DMARC isn’t just for bulk senders.
It’s for any organisation that doesn’t want criminals sending emails in its name.

The hidden risk many organisations discover

Another benefit of DMARC is visibility.

When reporting is enabled, many organisations discover services sending email on their behalf that were never properly configured.

Common examples include:

• website plugins sending contact form messages

• cloud software sending automated notifications

• marketing tools configured years ago

• legacy systems still using the domain

If these services fail authentication checks, they quietly damage your domain reputation.

That can make legitimate emails more likely to land in junk folders.

At Black Swan Cyber Security Solutions, we use Sendmarc to provide full DMARC visibility and reporting.

This allows us to:

• identify every service sending email from your domain

• correct authentication issues

• monitor email reputation

• gradually enforce stronger DMARC policies safely

The result is improved email trust and deliverability.

The security gap most businesses overlook

DMARC protects your outbound reputation.

It prevents criminals from impersonating your organisation.

However, DMARC does not stop malicious emails being delivered to your staff.

Even properly authenticated emails can still contain:

• phishing links

• malicious attachments

• supplier email compromise

• account takeover attempts

This is where many organisations still have a gap in their protection.

Once DMARC reporting is in place and your domain reputation is protected, the next step is strengthening inbound email security.

At Black Swan we deploy Check Point Harmony Email & Collaboration, which integrates directly with Microsoft 365 using secure API access.

Unlike traditional email gateways, this technology analyses messages inside the mailbox environment, allowing it to detect threats that may bypass standard filtering.

This helps stop:

• advanced phishing attacks

• compromised supplier emails

• malicious file payloads

• account takeover activity

Deliverability + security

When implemented properly, DMARC provides two key business benefits.

First, it improves email deliverability.

Your legitimate messages are trusted and more likely to reach the inbox.

Second, it protects your organisation from domain impersonation attacks.

When combined with modern email security, you also gain protection against malicious emails that target your team.

For many organisations, this combination closes one of the biggest security gaps in modern business communication.

Signs your organisation may need DMARC

You may benefit from DMARC services if:

• customers say they never received your emails

• important messages regularly land in junk folders

• you are unsure what systems send email using your domain

• you want to prevent criminals impersonating your organisation

• you rely on email for invoices, sales, or customer communication

Many organisations already have a DMARC record in DNS but it is set to monitoring only, which provides little protection.

Proper implementation requires reporting, analysis and policy enforcement.

What a managed DMARC service includes

A properly managed DMARC service typically includes:

• analysing current SPF, DKIM and DMARC records

• enabling DMARC reporting and monitoring

• identifying all legitimate sending services

• correcting authentication issues

• improving domain reputation

• moving towards stronger DMARC policies such as quarantine or reject

• ongoing monitoring and reporting

This ensures email authentication works without disrupting legitimate services.

DMARC services UK

If you’re searching for DMARC services in the UK, we help organisations:

• implement and manage DMARC reporting

• identify unknown email sources

• improve email deliverability

• protect domains from impersonation attacks

• strengthen Microsoft 365 email security

We work with schools, care providers, financial services firms and small businesses across Derbyshire, South Yorkshire and the rest of the UK.

Because email should help your organisation grow – not quietly disappear into the spam folder.

Want to know what’s really sending email from your domain?

Most organisations are surprised by what DMARC reporting reveals.

Legacy systems, website forms, forgotten marketing tools and cloud services can all be sending emails that affect your domain reputation.

At Black Swan Cyber Security Solutions, we use Sendmarc to analyse DMARC data, identify legitimate sending sources and help organisations safely enforce stronger protections.