Controlling who can forward or share emails within Microsoft 365 is about managing how sensitive information flows inside and outside your business. By setting clear restrictions on email forwarding and sharing, you reduce the risk of accidental data leaks, maintain compliance with UK data protection laws, and protect your company's reputation.
Why this matters for UK SMEs
For a small or medium-sized business in the UK, unchecked email forwarding can lead to serious issues. For example, an employee might unintentionally forward a confidential client proposal or personal data to an unauthorised recipient. This can cause data breaches, which may result in fines under the UK GDPR and Data Protection Act 2018, damage customer trust, and disrupt business operations.
Moreover, controlling email sharing helps prevent phishing attacks and limits the spread of malware. If an attacker compromises one account, restrictions on forwarding can reduce their ability to propagate malicious emails internally or externally.
A practical scenario
Consider a UK-based SME with 80 staff handling sensitive client information daily. Without restrictions, an employee accidentally forwards a spreadsheet containing personal data to a competitor. The business faces an ICO investigation, reputational damage, and costly remediation.
Working with a managed IT provider, the business implements Microsoft 365's Exchange Online mail flow rules and sensitivity labels. These tools prevent forwarding of emails marked as confidential and restrict external sharing. The IT partner also configures audit logging and alerts to monitor any attempts to bypass these controls, helping the business stay compliant and reduce risk.
Practical checklist to control email forwarding and sharing
- Review your Microsoft 365 settings: Check if mail flow rules (also called transport rules) are in place to block or limit forwarding of sensitive emails.
- Use sensitivity labels: Apply labels that classify emails as confidential and configure them to restrict forwarding and external sharing.
- Enable mailbox auditing and alerts: Ensure audit logs are turned on to track forwarding actions and set up alerts for unusual forwarding behaviour.
- Implement Multi-Factor Authentication (MFA): MFA reduces the risk of compromised accounts being used to forward emails maliciously.
- Ask your IT provider: How do you configure and monitor email forwarding restrictions? Can you provide reports on forwarding activity? How do you handle exceptions?
- Train staff: Regularly remind employees about the risks of forwarding sensitive information and how to use Microsoft 365's sharing controls properly.
- Check compliance readiness: Ensure your policies align with UK GDPR and Cyber Essentials requirements regarding data sharing and access control.
Controlling email forwarding and sharing in Microsoft 365 is a key part of protecting your business data and maintaining trust with customers and partners. If you're unsure how to set this up or want to review your current controls, speak with a trusted managed IT provider or IT advisor. They can assess your environment, recommend appropriate configurations, and help you stay secure and compliant without disrupting your day-to-day operations.