Microsoft 365 E5 shops looking to consolidate (Defender for O365 wins), cost-sensitive mid-market (Barracuda or Defender cheaper), or modern AI-behavioral leadership buyers (Abnormal wins on detection).
Large regulated enterprises (financial services, healthcare, federal) wanting a mature SEG with the broadest archive / DLP / compliance bundle and willing to pay premium pricing under PE ownership.
Why we say this
Editorial pulled these weaknesses from Proofpoint’s product card in our Top 10 Email Security Software for 2026:
- ! PE-driven price escalation aggressive (10-20% annual increases reported under Thoma Bravo)
- ! Behavioral AI lags Abnormal despite Tessian acquisition still integrating
- ! Platform UX feels heavy, multiple admin consoles, slow analyst workflows
- ! Microsoft Defender for O365 erodes installed base on every M365 E5 renewal
- ! Customer support quality declined post-2021 take-private
- ! Pricing opaque; channel-controlled with limited public transparency
If Proofpoint is wrong for you, consider these instead
Same Email Security Software category, different best-fit buyer.
Best for
Enterprises (1,000-100,000+ employees) on Microsoft 365 or Google Workspace adding an AI-behavioral overlay on top of Defender for O365 or a legacy SEG to catch BEC, ATO, and vendor email compromise.
See full profile →Best for
Mid-market and enterprise buyers (500-50,000 employees) wanting an integrated bundle of email security + continuity + archive + awareness training under a single vendor, particularly in the UK and EU.
See full profile →Best for
Any organization on Microsoft 365 E5 (essentially standard at zero marginal cost), or M365 E3 / Business Premium organizations adding Defender for O365 Plan 2 standalone.
See full profile →Related editorial
Last updated 2026-05-09. Editorial verdict based on the published Top 10 Email Security Software for 2026 ranking. Disagree? Tell us.