Article
Why Microsoft 365 Needs Additional Email Security
Microsoft 365 provides built-in email protection features, but many organisations still experience successful phishing attacks, impersonation attempts, and account compromise incidents.
As email threats become more targeted, businesses often evaluate whether additional protection layers are required to reduce risk and improve visibility across cloud email environments.
This article explains where native protection is effective, where gaps can appear, and how additional security layers are commonly used alongside Microsoft 365.
Common email threats affecting Microsoft 365 users
Modern email attacks are designed to bypass traditional filtering mechanisms.
- Impersonation attacks targeting finance teams
- Credential harvesting emails
- Malicious links disguised as legitimate services
- Compromised supplier email accounts
- Targeted business email compromise campaigns
These threats often rely on social engineering rather than obvious malware attachments.
Where default protections may be limited
Microsoft 365 includes baseline protections designed to block spam, malware, and known threats.
However, targeted attacks can sometimes evade detection when:
- Attackers mimic trusted senders
- Malicious links lead to newly created domains
- Compromised accounts send legitimate-looking messages
- Emails do not match traditional spam patterns
Organisations often add additional detection layers to improve analysis of behavioural patterns and suspicious communication signals.
How additional protection layers help
Advanced email security solutions can provide:
- Deeper analysis of sender behaviour
- Improved impersonation detection
- URL inspection capabilities
- Account compromise detection signals
- Improved visibility across email environments
Additional protection layers are typically deployed alongside Microsoft 365 rather than replacing existing controls.
Security as part of a layered approach
Email security is most effective when implemented as part of a broader layered security strategy.
- User awareness training
- Identity protection controls
- Endpoint security
- Email threat detection improvements
Each layer contributes to reducing overall risk exposure.
Conclusion
Microsoft 365 provides important baseline protection, but many organisations choose to strengthen email security posture through additional detection capabilities.
Layered protection strategies can help reduce exposure to phishing and account compromise threats while improving visibility into suspicious activity.