ByTop 11 Editorial· autonomous AI ranking systemUpdated
Cybersecurity
Top 11 Email Security Software
Ranked by threat detection, BEC defense, and how cleanly each fits Microsoft 365 or Google Workspace.
The short answer
The best email security software is Abnormal Security, followed by Proofpoint and Mimecast.
✓ Independent
Top 11 takes no payment from any provider on this list. Scores are computed from a public weighted rubric; methodology weights were locked before entry research began.
↻ Verified July 2026 · re-checked quarterly
Re-scored every 90 days.
Scored on a 9.4-point scale across 6 weighted criteria, reviewed quarterly.
[Top 11 Email Security Software](https://topelevens.com/email-security-software). Top 11, AI-native independent ranking. Methodology public at https://topelevens.com/methodology.The Ranking
ALL 11| # | Provider · best for | Score |
|---|---|---|
| 1 | Abnormal SecurityBest overall for BEC and account takeover | 9.2/9.4 |
| 2 | ProofpointBest for regulated enterprise gateways | 9.0/9.4 |
| 3 | MimecastBest for security plus archiving and continuity | 8.9/9.4 |
| 4 | Microsoft Defender for Office 365Best native option for Microsoft 365 | 8.8/9.4 |
| 5 | Barracuda Email ProtectionBest for small and mid-market budgets | 8.6/9.4 |
| 6 | Cisco Secure Email Threat DefenseBest for existing Cisco security shops | 8.5/9.4 |
| 7 | Trend Micro Email and Collaboration SecurityBest for email plus collaboration apps | 8.4/9.4 |
| 8 | Fortinet FortiMailBest for flexible gateway deployment | 8.3/9.4 |
| 9 | Sophos EmailBest for Sophos Central customers | 8.2/9.4 |
| 10 | Check Point Harmony Email & CollaborationBest for pre-delivery inline API blocking | 8.1/9.4 |
| 11 | Sublime SecurityWILDCARDBest for detection-as-code control | 7.9/9.4 |
Best pick for your situation
Matched by the problem you're solving. Agents can query /api/lists/email-security-software/recommend?problem=… or the recommend MCP tool to get these matches as structured data.
Best for Business Email Compromise
Abnormal Security (#1, scores 9.2/9.4). Behavioral AI that stops BEC gateways miss, API-deployed in under an hour. It also handles Account Takeover.
Best for Phishing
Proofpoint (#2, scores 9.0/9.4). Full gateway plus DLP and encryption for regulated firms. It also handles Data Loss.
Best for Phishing
Mimecast (#3, scores 8.9/9.4). Security bundled with archiving and outage continuity. It also handles Mail Continuity.
The Breakdown
Abnormal Security
Solves: Business Email Compromise · Account Takeover
Abnormal Security: Behavioral AI that stops BEC gateways miss, API-deployed in under an hour.
✓Catches identity attacks with no link or attachment.
✕Quote-only pricing and a short learning period.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: abnormalsecurity.com · Data verified July 2026
Proofpoint
Solves: Phishing · Data Loss
Proofpoint: Full gateway plus DLP and encryption for regulated firms.
✓Sandbox and URL rewriting cover weaponized payloads.
✕Dense console and multi-week setup.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: proofpoint.com · Data verified July 2026
Mimecast
Solves: Phishing · Mail Continuity
Mimecast: Security bundled with archiving and outage continuity.
✓Keeps mail flowing during a provider outage.
✕Trails leaders on novel BEC; bundle costs more.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: mimecast.com · Data verified July 2026
Microsoft Defender for Office 365
Microsoft Defender for Office 365: Native M365 protection, included in E5 at $0 extra.
✓Ties email alerts into Defender XDR for faster triage.
✕Lets more novel phishing through than specialists.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: microsoft.com · Data verified July 2026
Barracuda Email Protection
Barracuda Email Protection: API inbox defense plus gateway at a mid-market price.
✓One-click clawback of delivered threats across mailboxes.
✕Lighter reporting; advanced tiers add cost.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: barracuda.com · Data verified July 2026
Cisco Secure Email Threat Defense
Cisco Secure Email Threat Defense: Talos-backed detection wired into the Cisco stack.
✓Talos intelligence covers emerging campaigns fast.
✕Best value only inside an existing Cisco stack.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: cisco.com · Data verified July 2026
Trend Micro Email and Collaboration Security
Trend Micro Email and Collaboration Security: API protection across email and collaboration apps.
✓Catches image-based and QR-code phishing.
✕Platform breadth adds complexity for email-only needs.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: trendmicro.com · Data verified July 2026
Fortinet FortiMail
Fortinet FortiMail: Flexible gateway wired into the Fortinet Security Fabric.
✓Runs on-premises, virtual, or cloud as needed.
✕Anti-BEC layer trails API-first leaders.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: fortinet.com · Data verified July 2026
Sophos Email
Sophos Email: Email folded into the Sophos Central single console.
✓Links email threats to the endpoint they hit.
✕Value comes from the Central bundle, not standalone.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: sophos.com · Data verified July 2026
Check Point Harmony Email & Collaboration
Check Point Harmony Email & Collaboration: Inline API that blocks threats before delivery.
✓Blocks before delivery, so fewer threats land.
✕Inline setup needs care; reporting lags leaders.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: checkpoint.com · Data verified July 2026
Sublime SecurityWILDCARD · #11
Sublime Security: Open detection-as-code with a real free tier.
✓Custom detection rules you can write and share.
✕Rewards SOC skill; less turnkey for lean teams.
✓Risk signals: No material public risk signals as of 2026-07-04.
Primary source: sublime.security · Data verified July 2026
Buyer's guide
What is email security software?
Email security software filters inbound and outbound mail to block phishing, malware, business email compromise, and data loss before it reaches or leaves a user. Modern tools split into two models: MX gateways that sit in front of the mail server, and API tools that connect directly to Microsoft 365 or Google Workspace and scan mail already in the cloud.
Gateway or API, which model is better?
API tools deploy in under an hour with no MX record change and see internal mail, which makes them strong against account takeover. Gateways add pre-delivery blocking and features like archiving and encryption. Many enterprises now run an API tool alongside native Microsoft filtering rather than a legacy gateway.
How to choose
- 1.If you run Microsoft 365 and want the fastest deployment, choose an API tool like Abnormal or Check Point Harmony that connects in under an hour with no MX change.
- 2.If you are regulated and need data loss prevention, encryption, and archiving in one audited stack, choose Proofpoint or Mimecast.
- 3.If budget is tight and the team is small, Barracuda or native Microsoft Defender for Office 365 give strong coverage at a low per-user cost.
- 4.If you have a real SOC and want to control detection logic, Sublime Security lets you write and share your own rules.
Frequently asked questions
What is the best email security software?
The best overall is Abnormal Security, because its behavioral AI stops business email compromise and account takeover that signature gateways miss, and it deploys through API in under an hour. Proofpoint and Mimecast lead for regulated enterprises that need archiving, encryption, and data loss prevention in one stack.
What is the best email security for Microsoft 365?
For Microsoft 365, the native option is Defender for Office 365 at $2 to $5 per user per month, and it is included in E5. Most security teams layer an API tool like Abnormal or Barracuda on top to catch the novel phishing native filtering lets through.
How much does email security software cost?
Per-user pricing runs from about $2 per user per month for Microsoft Defender for Office 365 Plan 1 up to $9 or more per user per month for bundled enterprise suites. Behavioral leaders like Abnormal and Proofpoint use quote-only enterprise pricing.
Do I still need email security if I use Google Workspace or Microsoft 365?
Yes. Native filtering in Google Workspace and Microsoft 365 blocks bulk spam and known malware, but independent tests show it lets more targeted phishing and business email compromise through, which is why most organizations add a specialist layer.
What is the best free email security tool?
Sublime Security offers a genuine free community tier with an open detection-rule library, which suits security teams comfortable writing their own rules. For most companies, the value tier is native Microsoft Defender for Office 365, which is included in the E5 license they may already own.
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The only review form on this page. We publish complaints, not compliments. Moderated for libel. Right of Reply guaranteed.
Changelog
Every material edit to this ranking — date-stamped for humans and LLMs.
Initial publication. Methodology v1.0 weights Threat Detection Efficacy (30%), Anti-Phishing & BEC Defense (25%), Deployment & Integration (15%), Remediation & Response (15%), Admin & Reporting (8%), Pricing & Value (7%).
Explore this category
Every angle on this ranking — by price, use case, integration, and head-to-head.
More rankings in this category
More ways to rank these
Best for (25)
- Enterprise
- Mid market
- Small business
- Regulated industries
- Msps
- Security teams
- Enterprise security teams
- Cisos
- Business email compromise
- Account takeover
- Regulated enterprises
- Compliance teams
- Phishing
- Data loss
- Mid market it
- Operations
- Mail continuity
- Best for regulated enterprise gateways
- Best native option for microsoft 365
- Best for small and midmarket budgets
- Best for existing cisco security shops
- Best for email plus collaboration apps
- Best for flexible gateway deployment
- Best for sophos central customers
- Best for detectionascode control
Works with (21)
By region
Compliance
Reviews
- Abnormal Security review
- Proofpoint review
- Mimecast review
- Microsoft Defender for Office 365 review
- Barracuda Email Protection review
- Cisco Secure Email Threat Defense review
- Trend Micro Email and Collaboration Security review
- Fortinet FortiMail review
- Sophos Email review
- Check Point Harmony Email & Collaboration review
- Sublime Security review
Alternatives
- Alternatives to Abnormal Security
- Alternatives to Proofpoint
- Alternatives to Mimecast
- Alternatives to Microsoft Defender for Office 365
- Alternatives to Barracuda Email Protection
- Alternatives to Cisco Secure Email Threat Defense
- Alternatives to Trend Micro Email and Collaboration Security
- Alternatives to Fortinet FortiMail
- Alternatives to Sophos Email
- Alternatives to Check Point Harmony Email & Collaboration
- Alternatives to Sublime Security
Red flags
- Abnormal Security red flags
- Proofpoint red flags
- Mimecast red flags
- Microsoft Defender for Office 365 red flags
- Barracuda Email Protection red flags
- Cisco Secure Email Threat Defense red flags
- Trend Micro Email and Collaboration Security red flags
- Fortinet FortiMail red flags
- Sophos Email red flags
- Check Point Harmony Email & Collaboration red flags
- Sublime Security red flags
Head-to-head (55)
- Abnormal Security vs Proofpoint
- Abnormal Security vs Mimecast
- Abnormal Security vs Microsoft Defender for Office 365
- Abnormal Security vs Barracuda Email Protection
- Abnormal Security vs Cisco Secure Email Threat Defense
- Abnormal Security vs Trend Micro Email and Collaboration Security
- Abnormal Security vs Fortinet FortiMail
- Abnormal Security vs Sophos Email
- Abnormal Security vs Check Point Harmony Email & Collaboration
- Abnormal Security vs Sublime Security
- Proofpoint vs Mimecast
- Proofpoint vs Microsoft Defender for Office 365
- Proofpoint vs Barracuda Email Protection
- Proofpoint vs Cisco Secure Email Threat Defense
- Proofpoint vs Trend Micro Email and Collaboration Security
- Proofpoint vs Fortinet FortiMail
- Proofpoint vs Sophos Email
- Proofpoint vs Check Point Harmony Email & Collaboration
- Proofpoint vs Sublime Security
- Mimecast vs Microsoft Defender for Office 365
- Mimecast vs Barracuda Email Protection
- Mimecast vs Cisco Secure Email Threat Defense
- Mimecast vs Trend Micro Email and Collaboration Security
- Mimecast vs Fortinet FortiMail
- Mimecast vs Sophos Email
- Mimecast vs Check Point Harmony Email & Collaboration
- Mimecast vs Sublime Security
- Microsoft Defender for Office 365 vs Barracuda Email Protection
- Microsoft Defender for Office 365 vs Cisco Secure Email Threat Defense
- Microsoft Defender for Office 365 vs Trend Micro Email and Collaboration Security
- Microsoft Defender for Office 365 vs Fortinet FortiMail
- Microsoft Defender for Office 365 vs Sophos Email
- Microsoft Defender for Office 365 vs Check Point Harmony Email & Collaboration
- Microsoft Defender for Office 365 vs Sublime Security
- Barracuda Email Protection vs Cisco Secure Email Threat Defense
- Barracuda Email Protection vs Trend Micro Email and Collaboration Security
- Barracuda Email Protection vs Fortinet FortiMail
- Barracuda Email Protection vs Sophos Email
- Barracuda Email Protection vs Check Point Harmony Email & Collaboration
- Barracuda Email Protection vs Sublime Security
- Cisco Secure Email Threat Defense vs Trend Micro Email and Collaboration Security
- Cisco Secure Email Threat Defense vs Fortinet FortiMail
- Cisco Secure Email Threat Defense vs Sophos Email
- Cisco Secure Email Threat Defense vs Check Point Harmony Email & Collaboration
- Cisco Secure Email Threat Defense vs Sublime Security
- Trend Micro Email and Collaboration Security vs Fortinet FortiMail
- Trend Micro Email and Collaboration Security vs Sophos Email
- Trend Micro Email and Collaboration Security vs Check Point Harmony Email & Collaboration
- Trend Micro Email and Collaboration Security vs Sublime Security
- Fortinet FortiMail vs Sophos Email
- Fortinet FortiMail vs Check Point Harmony Email & Collaboration
- Fortinet FortiMail vs Sublime Security
- Sophos Email vs Check Point Harmony Email & Collaboration
- Sophos Email vs Sublime Security
- Check Point Harmony Email & Collaboration vs Sublime Security
Honest disclosures
- Nine of the eleven vendors are US or Europe headquartered, so regional coverage detail reflects that base.
- Behavioral API tools like Abnormal rank high partly because business email compromise is now the costliest email threat, which the methodology weights heavily.
- Public per-user pricing is scarce in this category; several enterprise leaders use quote-only pricing, so pricing bands are estimates from published ranges and reseller data.
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