If you’re evaluating Cisco Secure Email for email security software, the three strongest independent alternatives in our editorial ranking are Abnormal Security, Proofpoint, Mimecast. Each has a different best-fit buyer — the right choice depends on team size and workflow, not on which has the loudest review-site presence.
Why Cisco Secure Email sometimes isn’t the right pick: Non-Cisco shops (Defender for O365 or Abnormal better), modern cloud-native organizations (any of the modern AI-behavioral leaders win), or buyers wanting transparent pricing. See full “worst for” verdict →
9 Cisco Secure Email alternatives
| Rank | Product | Best for | Target size | Pricing |
|---|---|---|---|---|
| #1 | Abnormal Security | 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. | 500–100,000+ | ○ Quote-only |
| #2 | Proofpoint | 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. | 1,000–500,000+ | ○ Quote-only |
| #3 | Mimecast | 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. | 500–50,000+ | ○ Quote-only |
| #4 | Microsoft Defender for Office 365 | 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. | 1–500,000+ | ● Transparent |
| #6 | Barracuda Email Protection | Mid-market organizations (200-5,000 employees) wanting integrated email security + backup + archive + awareness training under a single mid-market-priced vendor, often through MSPs. | 200–10,000 | ◐ Partial |
| #7 | Avanan | Organizations on Check Point Infinity / Harmony stacks (firewall, endpoint, SASE) wanting unified email security as part of a single Check Point platform. | 500–50,000+ | ○ Quote-only |
| #8 | Sublime Security | Detection-engineering security teams (200-20,000 employees) that already write custom Sigma, YARA, or Snort rules and want the same level of control and transparency over email detection logic. | 50–20,000 | ◐ Partial |
| #9 | Material Security | Security-mature organizations (1,000-50,000 employees) that have accepted that mailboxes will eventually be compromised and want to limit the blast radius, particularly financial services, legal, and high-IP-value verticals. | 500–50,000 | ◐ Partial |
| #10 | Vade | European mid-market organizations (200-10,000 employees) prioritizing French / European data residency, and ISPs / telcos protecting consumer and SMB mailboxes at scale via OEM. | 200–10,000 | ◐ Partial |
Which alternative for which buyer
Abnormal Security
AI-driven behavioral anomaly detection, modern category leader for BEC, ATO, and vendor email compromise.
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.
Cost-sensitive SMBs (Defender for Business or Microsoft 365 Business Premium cheaper), on-prem Exchange shops (unsupported), or buyers wanting a single replacement gateway rather than an additive overlay.
Proofpoint
Largest legacy enterprise SEG installed base; Tessian acquisition added behavioral AI.
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.
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).
Mimecast
Legacy SEG with mature archiving and awareness training bundle; PE-owned post-2022.
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.
Microsoft 365 E5 shops consolidating (Defender for O365 wins), modern AI-behavioral leadership buyers (Abnormal wins), or buyers wanting transparent pricing.
Microsoft Defender for Office 365
Bundled with M365 E5, the de facto default for Microsoft-anchored organizations.
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.
Google Workspace organizations (Defender does not protect Google Workspace), buyers prioritizing best-in-class behavioral AI for BEC/ATO (Abnormal wins as overlay), or non-Microsoft enterprises generally.
Barracuda Email Protection
Mid-market email + backup + archive bundle; KKR-owned post-2022.
Mid-market organizations (200-5,000 employees) wanting integrated email security + backup + archive + awareness training under a single mid-market-priced vendor, often through MSPs.
Large enterprises (10,000+ employees) where Proofpoint, Mimecast, or Defender win, modern AI-behavioral leadership buyers (Abnormal wins), or buyers wanting transparent pricing.
Avanan
Cloud-anchored API-integrated email security; tight Check Point Infinity integration.
Organizations on Check Point Infinity / Harmony stacks (firewall, endpoint, SASE) wanting unified email security as part of a single Check Point platform.
Non-Check Point shops (Defender for O365 or Abnormal better), modern AI-behavioral leadership buyers (Abnormal wins), or buyers wanting transparent pricing.
Related editorial
Last updated 2026-05-09. Rankings reflect editorial judgment based on the published Top 10 Email Security Software for 2026. We accept no vendor payments. Found something inaccurate? Tell us.