Proofpoint vs Microsoft Defender for Office 365

Side-by-side from the Top 11 ranking of Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026. Last verified July 4, 2026.

The short answer

Proofpoint ranks higher on Top 11 (#2 vs #4) for IT and security leaders. Full gateway plus DLP and encryption for regulated firms.

At a glance

ProofpointMicrosoft Defender for Office 365
Top 11 rank#2 / Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026#4 / Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026
Score (out of 9.4)98.8
Best forBest for regulated enterprise gatewaysBest native option for Microsoft 365
Pricing$$$ (custom, per-user enterprise pricing)$ ($2/user/mo Plan 1, $5/user/mo Plan 2, or bundled in E5)
HQSunnyvale, USARedmond, USA
Founded20022015

Methodology and scoring weights live at /methodology. No vendor pays for placement — see about.