Why Business Email Compromise remains the top threat and how Mimecast plus a layered approach can help.
Heading into 2026, many organisations believe their email security posture is “sorted”. After all, they’re running Microsoft 365, with built-in anti-spam and malware protection. But the uncomfortable truth is this: Business Email Compromise (BEC) remains one of the leading causes of cyber attacks against UK organisations and standard tools simply aren’t enough.
At C4C Group, we see this first-hand. As an Authorised UK Reseller and Trusted Partner for Mimecast, we help organisations build advanced, layered defences that go far beyond the limitations of default email security. Our perspective is grounded in vendor-side experience and a proven framework that aligns technology, human risk, and measurable business value.
Email remains the top entry point for attacks
It’s tempting to assume that because most organisations have email gateways and anti-phishing tools, they’re protected. But the data tells a different story.
According to the Mimecast State of Human Risk Report 2025 and the Verizon Data Breach Investigations Report 2024, email remains the most exploited attack vector globally responsible for over 90% of initial compromise attempts.
Attackers continue to exploit the human element impersonation, social engineering, and AI-powered phishing — to bypass traditional defences.
In short: attackers know email is still the easiest way in, and they’re not slowing down.
Why standard tools like Microsoft 365 alone aren’t enough
Microsoft 365 provides a solid foundation, but it’s not designed to address every modern threat. Attackers increasingly exploit trusted applications and collaboration tools to “blend in” and evade detection.
Even Microsoft acknowledges that “no single layer of defence is sufficient” (Microsoft Security Blog), recommending that organisations adopt a multi-layered approach to protection — something we see validated daily in real-world client environments.
- Most breaches today involve social engineering or credential theft, not just malicious attachments.
- Standard filters miss context-based threats such as invoice fraud, supplier impersonation, and executive spoofing.
- Native defences lack post-delivery protection, behavioural analytics, and human-risk insight.
Without a multi-layered defence, organisations risk blind spots that sophisticated attackers exploit every day.
The layered, human-risk-centric approach: why it matters
At C4C Group, our differentiation is clear: we don’t just sell products we build trust through expertise. As a Mimecast Authorised Partner, we design and implement multi-layered email security architectures that combine technology, policy, and behavioural defence.
1. Technology Layer – Mimecast Email Security Platform
As one of Mimecast’s UK-based authorised resellers, we help clients deploy:
- Advanced email threat detection (BEC, phishing, impersonation)
- Collaboration-tool protection (Teams, Slack, etc.)
- Post-delivery protection and anomaly detection
- AI-powered threat intelligence and human-risk analytics
Mimecast’s leadership in email security is recognised globally. Learn more on the Mimecast Email Security page.
Our partnership ensures clients receive local, expert guidance on configuration, compliance, and integration.
2. Policy & Process Layer
We align Mimecast’s controls with your governance and security policies, ensuring compliance and operational efficiency.
3. People & Awareness Layer
Human error remains the biggest risk. We provide tailored awareness programmes and phishing simulation training to strengthen your “human firewall”.
4. Continuous Monitoring & Threat Intelligence
Through ongoing vendor insight and proactive support, C4C Group ensures your Mimecast environment continues to evolve alongside new threat patterns.
Why BEC remains such a major threat
BEC (Business Email Compromise) attacks exploit trust and human behaviour, not just technical weaknesses.
They target finance, HR, and executive teams, often impersonating internal or supplier contacts to trigger fraudulent payments or data exposure.
The UK’s National Cyber Security Centre (NCSC) continues to warn that BEC remains one of the most financially damaging types of cyber attack affecting UK businesses.
Mimecast’s research confirms that human risk is now the top security priority heading into 2026. Unless you address the intersection of human + process + technology, your organisation remains exposed.
What to do next — 5 practical steps
As a UK-based Mimecast Partner and Authorised Reseller, C4C Group can guide you through assessment, procurement, and deployment ensuring your email security investment delivers measurable value.
- Assess your current posture – Identify gaps in Microsoft 365’s native coverage.
- Deploy an advanced email security platform – Implement Mimecast to extend protection and visibility.
- Strengthen authentication – Enforce MFA and ensure DMARC, SPF, and DKIM are configured.
- Invest in awareness training – Reduce human risk through phishing simulations and staff education.
- Monitor continuously – Maintain active threat intelligence and vendor oversight.
Conclusion
If you believe your email security is “done” for 2026, think again. BEC and social engineering remain the dominant threat vectors, and traditional tools alone can’t keep up.
By partnering with a trusted, UK-based Mimecast expert like C4C Group, you gain layered protection, measurable value, and confidence in an ever-evolving threat landscape.
For additional best-practice guidance, frameworks such as Cyber Essentials and the NIST Cybersecurity Framework offer useful benchmarks for resilience.
C4C Group — Simplifying Innovation. Securing the Human Layer.