How a financial institution closed email security gaps by replacing Mimecast with Proofpoint

Key takeaways

• A data loss protection (DLP) project uncovered critical blind spots in a company's email security.
• Proofpoint gave the team deep visibility into internal threats and data risk.
• A more unified approach to email and data security enabled the company to achieve measurable improvements in both risk reduction and operational performance.

A regional financial institution set out to strengthen Microsoft Purview DLP. What it uncovered instead were broader gaps in its email security visibility and operational efficiency.

The organization had been running Mimecast for email security alongside Microsoft’s native data protection controls. While the stack supported its Microsoft 365 environment, the security team lacked sufficient visibility into lateral phishing and email-based data exfiltration. Investigation workflows were slow and operationally heavy. This made it difficult for the team to assess and respond to email-based risk effectively.

A project that began as an initiative to augment a data loss prevention (DLP) tool ultimately grew into a broader reassessment of the organization’s strategy for email security.

The challenge: closing visibility gaps in a regulated environment

Microsoft Purview DLP covered foundational use cases. However, the organization required deeper, centralized visibility across email, endpoints, and cloud environments to manage risk confidently. Specifically, the security team sought stronger protection against:

• Misdirected email and misattached files
• Email-based data exfiltration
• Insider risk and policy violations
• Lateral phishing and business email compromise

Without insight into internal user-to-user email activity, it was difficult to detect threats moving laterally within Microsoft 365. In a highly regulated financial environment, this lack of clarity was unsustainable.

What’s more, there wasn’t much consistency when it came to detecting these threats. And the security center operation (SOC) team had to spend a lot of time and effort on investigating and remediating issues. 

The evaluation: extending Microsoft with greater visibility and efficiency

The organization launched a project to identify a solution that could:

• Extend Microsoft Purview DLP with behavioral and contextual intelligence
• Provide centralized visibility across email, endpoints, and cloud
• Improve investigation and remediation workflows
• Maintain Microsoft as the foundation of its security ecosystem

As the project progressed, it became clear that resolving DLP gaps wasn’t a simple issue. They also needed deeper visibility into internal email and stronger post-delivery detection capabilities than their existing Mimecast deployment could provide.

In a long list of potential solutions, Proofpoint stood out for its ability to deliver what they needed. It provided deep visibility while aligning closely with the organization’s Microsoft strategy. Plus, it enabled the organization to gain insight into lateral phishing, compromised account activity, and potential data exfiltration scenarios that it had not been able to fully assess.

The outcome: stronger protection and greater efficiency

Ultimately, the organization replaced Mimecast with Proofpoint while continuing to use Microsoft as the foundation of its security. With a more unified approach to email and data security, it achieved measurable improvements in both risk reduction and operational performance.

From a DLP standpoint, Proofpoint supported a broader range of use cases, including screen capture monitoring for suspected policy violations. And from an email security perspective, it offered:

• Expanded internal visibility
• Advanced search capabilities for proactive threat hunting
• Intuitive, automated remediation workflows

Together, these enhancements allowed the organization to close critical visibility gaps, strengthen protection in a regulated environment, and significantly improve SOC efficiency.

Conclusion

The organization transformed its security even though it had only expected to enhance its DLP capabilities. Because it evaluated Proofpoint, it found stronger protection, greater operational efficiency, and a more resilient foundation for its security built on Microsoft. 

Organizations that rely on native Microsoft controls or legacy email security platforms should evaluate whether they have full visibility into internal threats and data movement. When you enhance Microsoft with Proofpoint, you get advanced email security and data protection capabilities. This ensures you can close critical gaps, reduce risk, and improve SOC team efficiency.

See how Proofpoint enhances Microsoft 365 security. 

Compare Proofpoint to Mimecast to understand how organizations strengthen protection and close security gaps.