Microsoft Defender for Office 365 alternatives (2026)
9 email security tools listed alongside Microsoft Defender for Office 365 for side-by-side comparison on capabilities, pricing, and deployment. No editorial ranking.
Why look for Microsoft Defender for Office 365 alternatives?
Microsoft Defender for Office 365 is a strong option for email security, but it's not the right fit for every team. Common reasons teams look elsewhere: only protects microsoft 365. does not support google workspace or other platforms; detection efficacy for advanced threats historically behind proofpoint and mimecast.
Below we list 9 alternatives, broken down by deployment model. All data is aggregated from official documentation and community feedback.
Head-to-Head Comparisons
Microsoft Defender for Office 365 vs ProofpointMicrosoft Defender for Office 365 vs MimecastMicrosoft Defender for Office 365 vs Abnormal SecurityMicrosoft Defender for Office 365 vs Barracuda Email SecurityMicrosoft Defender for Office 365 vs Cisco Secure EmailMicrosoft Defender for Office 365 vs Trend Micro Email SecurityMicrosoft Defender for Office 365 vs IRONSCALESMicrosoft Defender for Office 365 vs TessianMicrosoft Defender for Office 365 vs Acronis Email Security