# Email security: what AI models recommend, September 2026

IT AI Recommendation Index, September 2026 Edition. Asked as "email security platform" and as "phishing and email threat protection tool", six framings each, to twelve models with search on, on behalf of a mid-market B2B company. Page: https://it-ai-index.com/security/email-security/

**Standing:** Microsoft Defender for Office 365 leads with 31% of first choices; verdict contested. 58 first choices across the direct, paraphrase, budget and scale prompts.

## First-choice share

| # | Product | Share | Negative rate | Labels |
|---|---|---|---|---|
| 1 | Microsoft Defender for Office 365 | 31% | 9% | 47 |
| 2 | Abnormal AI | 12% | 4% | 45 |
| 3 | Proofpoint Email Protection | 10% | 12% | 49 |
| 4 | Check Point Harmony Email & Collaboration | 10% | 8% | 26 |
| 5 | IRONSCALES | 9% | 0% | 29 |
| 6 | Mimecast Email Security | 7% | 13% | 45 |
| 7 | Barracuda Email Protection | 7% | 6% | 34 |
| 8 | SpamTitan | 5% | 7% | 15 |
| 9 | Cisco Secure Email | 0% | 27% | 11 |

## Each model's first choice on the direct prompt

- Claude Haiku 4.5: Barracuda Email Protection; alternatives Abnormal AI, Check Point Harmony Email & Collaboration
- GPT-5.4 mini: Microsoft Defender for Office 365; alternatives Proofpoint Email Protection
- Gemini 3.5 Flash: Abnormal AI, Check Point Harmony Email & Collaboration; alternatives IRONSCALES, Sophos Email, Sublime Security
- Perplexity Sonar: Mimecast Email Security; alternatives Proofpoint Email Protection
- Grok 4.1 Fast: Mimecast Email Security, Proofpoint Email Protection; alternatives Abnormal AI, Barracuda Email Protection
- Mistral Small: Barracuda Email Protection, Proofpoint Email Protection; alternatives Abnormal AI, Mimecast Email Security
- DeepSeek V4 Flash: Abnormal AI, Check Point Harmony Email & Collaboration, IRONSCALES; alternatives Barracuda Email Protection, Microsoft Defender for Office 365, Proofpoint Email Protection
- Llama 4 Maverick: Barracuda Email Protection; alternatives IRONSCALES, Proofpoint Email Protection, SpamTitan
- Qwen 3.7 Flash: Microsoft Defender for Office 365; alternatives Abnormal AI, Barracuda Email Protection, Mimecast Email Security, Proofpoint Email Protection
- Kimi K2: Abnormal AI, IRONSCALES; alternatives Barracuda Email Protection, Microsoft Defender for Office 365, Mimecast Email Security
- GLM 4.7 FlashX: Mimecast Email Security; alternatives Abnormal AI, Barracuda Email Protection, Egress, IRONSCALES
- MiniMax M2.5: Microsoft Defender for Office 365, Proofpoint Email Protection; alternatives Abnormal AI, Mimecast Email Security

## Sources the answers cite

64 of 72 answers came back with a source list, from 12 of 12 models. Sites named in the most answers:

- gartner.com: 43 answers, 49 citations
- expertinsights.com: 29 answers, 38 citations
- cybervendorguide.com: 23 answers, 23 citations
- sublime.security: 20 answers, 23 citations
- kaseya.com: 19 answers, 19 citations
- ironscales.com: 18 answers, 19 citations
- barracuda.com: 16 answers, 18 citations
- learn.g2.com: 16 answers, 16 citations

Pages named in the most answers:

- https://gartner.com/reviews/market/email-security (39 answers)
- https://cybervendorguide.com/guides/email-security (23 answers)
- https://kaseya.com/blog/best-email-security-solutions (19 answers)
- https://learn.g2.com/best-cloud-email-security-platforms (16 answers)
- https://expertinsights.com/email-security/top-email-security-gateways (15 answers)
- https://ironscales.com/blog/the-best-email-security-companies-rankings-and-reviews (15 answers)
- https://barracuda.com/support/glossary/best-email-security-companies (12 answers)
- https://cybersectools.com/resources/shortlists/best-email-security-platforms (11 answers)
- https://flamingo.run/blog/email-security-solutions (11 answers)
- https://sublime.security/articles/top-email-security-companies (11 answers)

## Warned against

- Mimecast Email Security: 6 of 45 labels negative. "it has experienced security breaches in the past, including a certificate compromise... This has led some organizations to approach Mimecast with caution." (Mistral Small, negative prompt)
- Proofpoint Email Protection: 6 of 49 labels negative. "Proofpoint is priced and configured for enterprise environments with significant operational complexity... it just may not be suitable for smaller organizations." (Claude Haiku 4.5, negative prompt)
- Barracuda Email Security Gateway: 3 of 6 labels negative. "Barracuda advised affected customers to replace devices. Ongoing exploits via third-party libraries ... have kept it risky." (Grok 4.1 Fast, negative prompt)
- Cisco Secure Email: 3 of 11 labels negative. "Status: Avoid or Patch Immediately" (GLM 4.7 FlashX, negative prompt)

## Record

- Method: https://it-ai-index.com/methodology/
- Raw judge labels and full responses: https://it-ai-index.com/data/
- License: CC BY 4.0. Cite as IT AI Recommendation Index, September 2026 Edition, it-ai-index.com.