Email security is the frontline of business defense, but is Microsoft Defender for Office 365 enough to keep your inbox secure? According to a recent analysis by Check Point, the answer is clear: businesses need more robust protection. Here’s why.
The Microsoft Defender challenge
Check Point’s research revealed that 18.8% of phishing emails bypass Microsoft Defender, an alarming increase of 74% compared to 2020. The reasons? Hackers are getting smarter and designing attacks specifically to evade Microsoft’s default defences. For larger organisations, the failure rate is even higher, with up to 70% of phishing emails slipping through.
While Microsoft Defender performs well against general malware, its ability to block sophisticated phishing attempts, such as financial scams or credential harvesting, falls short. For instance, 42% of financial phishing attacks bypassed Defender’s protection, leading to significant vulnerabilities in high-stakes industries.
Dumpster diving: A hidden threat
Microsoft Defender’s reliance on the Junk folder for quarantined emails creates another risk: “Dumpster Diving.” Legitimate and malicious emails often land in the same folder, encouraging users to sift through messages manually. This process exposes employees to phishing attacks disguised among harmless marketing emails.
One attack method even exploits this behavior directly. Hackers send follow-up emails instructing recipients to check their Junk folder, increasing the likelihood of the malicious email being opened. With 7% of phishing emails landing in Junk, the danger is real.
The cost to businesses
Managing email security gaps impacts more than just inboxes; it strains resources and teams. Check Point found that businesses relying solely on Microsoft Defender faced:
- 23% of SOC team time wasted on email threat management.
- 104 days per year spent on phishing investigations by large organisations.
These inefficiencies lead to burnout and divert attention from strategic priorities.
Avanan: The game-changer
Avanan, part of Check Point Harmony Email Security, is designed to tackle these challenges head-on. Sitting inline behind Microsoft Defender, Avanan uses AI and machine learning to block phishing, malware and targeted attacks before they reach the inbox. Here’s how it excels:
- Real-time AI protection: Avanan learns from Microsoft’s missed attacks, providing an added layer of security.
- Comprehensive threat coverage: From financial fraud to credential harvesting, Avanan significantly reduces risks across all phishing categories.
- Streamlined SOC workflow: By actively blocking threats, Avanan slashes the time and effort required for manual threat management.
Success by the numbers
When businesses adopted Avanan, they saw transformative results:
- 95% reduction in phishing incidents reported by users.
- SOC teams spent far less time investigating threats, reclaiming valuable hours for other critical tasks.
- Large organisations reduced false-positive reports, enabling teams to focus on real risks.
Why layering matters
A “defence-in-depth” strategy is no longer optional. With hackers constantly evolving their tactics, relying solely on Microsoft or any single email security solution is risky. Avanan ensures that businesses of all sizes, especially those handling sensitive data, remain secure.
While the Check Point analysis primarily focuses on larger organisations, the insights are just as relevant for smaller entities like schools and small businesses.
At Black Swan Cyber Security Solutions, we specialise in supporting Schools, MATs, and small businesses, providing tailored, budget-conscious email security solutions that align with their unique needs. Avanan’s scalable, AI-driven protection works seamlessly with Microsoft 365, offering the same robust defence against phishing, credential theft, and financial scams – without requiring an extensive IT team. Whether you’re safeguarding sensitive student data or ensuring your small business stays secure, Avanan can provide the peace of mind you need.
In 2025, email security isn’t just about protection; it’s about efficiency, scalability, and staying ahead of threats. Avanan delivers all three.
Let’s discuss how we can safeguard your business today.
