Cisco Secure Email Threat Defense (formerly Cloud Mailbox)

Advanced threat detection capabilities to protect against the most advanced and pervasive threats.

Secure Office 365 email against advanced threats

Moving email to the cloud provides convenience and scalability, but it could also bring an increased risk of account takeovers and malware infection. Secure Email Threat Defense is a cloud-focused email security solution that is simple to deploy and provides advanced threat detection to fully protect your business, user, and brand.

Comprehensive protection against damaging email threats

Advanced threat detection capabilities uncover known, emerging, and targeted threats. Expand the scope of your defenses to identify malicious techniques, gain context for specific business risks, detect dangerous threats, and rapidly search for and remediate threats across security controls. Get the protection that defends your organization's brand and operations.

Simple, powerful cloud email security


Secure Email Threat Defense is fully integrated into Microsoft 365 for complete visibility into inbound, outbound, and internal messages. Searchable threat telemetry categorizes threats and identifies which parts of your organization are most vulnerable to attack.


As an important part of a larger extended detection and response (XDR) strategy, Secure Email defends against critical threats with industry-leading threat intelligence, advanced threat detection capabilities, and vital telemetry that informs strategic threat protection.


The superior threat intelligence from Cisco Talos, the industry-leading threat intelligence organization, and integrations across the broad Cisco Secure portfolio, and with third-party partners, provides exceptional and actionable threat data. 



This 2-minute overview highlights new features and capabilities for securing Microsoft 365 email.

Protect every email and inbox in your small business

43% of all cyberattacks target small businesses. Learn how to protect your cloud email.

How to secure Microsoft 365 Email against advanced threats

This threat brief reveals why Microsoft 365 is a prime target for hackers, what the top five email threats are, and how you can minimize your risks.