Cybersecurity · Email Security
Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026
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.
The ranking
| Rank | Provider | Best for | Price band | Score out of 9.4 |
|---|---|---|---|---|
| 1 | Abnormal SecurityBest overall for BEC and account takeover | 9.2 | ||
| 2 | ProofpointBest for regulated enterprise gateways | 9.0 | ||
| 3 | MimecastBest for security plus archiving and continuity | 8.9 | ||
| 4 | Microsoft Defender for Office 365Best native option for Microsoft 365 | 8.8 | ||
| 5 | Barracuda Email ProtectionBest for small and mid-market budgets | 8.6 | ||
| 6 | Cisco Secure Email Threat DefenseBest for existing Cisco security shops | 8.5 | ||
| 7 | Trend Micro Email and Collaboration SecurityBest for email plus collaboration apps | 8.4 | ||
| 8 | Fortinet FortiMailBest for flexible gateway deployment | 8.3 | ||
| 9 | Sophos EmailBest for Sophos Central customers | 8.2 | ||
| 10 | Check Point Harmony Email & CollaborationBest for pre-delivery inline API blocking | 8.1 | ||
| 11 | Sublime SecurityWildcardBest for detection-as-code control | Unrated by designSignal read |
The field at a glance
What you pay against what you get. Anything up and to the left is punching above its price.
The wildcard · #11
Unrated by designSublime Security
This is not another managed email security service; it is a programmable platform for my security team to build and run our own detections as code.
The ten above are scored against the public rubric. The wildcard answers a different question, so it carries no score. It is selected by the wildcard signal model (wildcard-v2.0), read 2026-08-26.
- Under-the-radar coefficientexceptional
- Its quality for security teams who write code is much higher than its low market share relative to gateway incumbents suggests.
- Category fit anomalyexceptional
- It provides an open, programmable rule engine instead of the category's dominant closed-box, AI-driven detection model.
- Effort transferstrong
- The platform expects the customer's security team to write and maintain detection rules, requiring significant in-house engineering skill.
- Impact densitystrong
- The free community tier allows skilled teams to deploy custom, open source email detections for zero software cost.
- Founder attention proximitystrong
- The founding team and engineers actively participate in public communities, developing and sharing detection rules directly with users.
- Lock-in costnotable
- Detection logic is expressed in an open query language and shared in a public library, making it more portable than proprietary systems.
Right for
Organizations with a dedicated security operations center or detection engineering team that wants to write custom email threat detections.
Wrong for
IT teams without security engineering staff who need a fully managed, set-and-forget email security gateway.
Every entry
Abnormal Security
Behavioral AI that stops BEC gateways miss, API-deployed in under an hour.
- Best for
- Best overall for BEC and account takeover
- $$$
- custom, per-mailbox enterprise pricing
- Company
- San Francisco, USA · est. 2018
Catches identity attacks with no link or attachment.
Quote-only pricing and a short learning period.
- Business Email Compromise
- Account Takeover
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Proofpoint
Full gateway plus DLP and encryption for regulated firms.
- Best for
- Best for regulated enterprise gateways
- $$$
- custom, per-user enterprise pricing
- Company
- Sunnyvale, USA · est. 2002
Sandbox and URL rewriting cover weaponized payloads.
Dense console and multi-week setup.
- Phishing
- Data Loss
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Mimecast
Security bundled with archiving and outage continuity.
- Best for
- Best for security plus archiving and continuity
- $$
- roughly $4 to $9 per user per month
- Company
- London, UK · est. 2003
Keeps mail flowing during a provider outage.
Trails leaders on novel BEC; bundle costs more.
- Phishing
- Mail Continuity
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Microsoft Defender for Office 365
Native M365 protection, included in E5 at $0 extra.
- Best for
- Best native option for Microsoft 365
- $
- $2/user/mo Plan 1, $5/user/mo Plan 2, or bundled in E5
- Company
- Redmond, USA · est. 2015
Ties email alerts into Defender XDR for faster triage.
Lets more novel phishing through than specialists.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Barracuda Email Protection
API inbox defense plus gateway at a mid-market price.
- Best for
- Best for small and mid-market budgets
- $$
- roughly $3 to $7 per user per month
- Company
- Campbell, USA · est. 2003
One-click clawback of delivered threats across mailboxes.
Lighter reporting; advanced tiers add cost.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Cisco Secure Email Threat Defense
Talos-backed detection wired into the Cisco stack.
- Best for
- Best for existing Cisco security shops
- $$$
- custom, per-user enterprise pricing
- Company
- San Jose, USA · est. 1984
Talos intelligence covers emerging campaigns fast.
Best value only inside an existing Cisco stack.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Trend Micro Email and Collaboration Security
API protection across email and collaboration apps.
- Best for
- Best for email plus collaboration apps
- $$
- roughly $3 to $6 per user per month
- Company
- Tokyo, Japan · est. 1988
Catches image-based and QR-code phishing.
Platform breadth adds complexity for email-only needs.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Fortinet FortiMail
Flexible gateway wired into the Fortinet Security Fabric.
- Best for
- Best for flexible gateway deployment
- $$
- appliance or per-user cloud, custom
- Company
- Sunnyvale, USA · est. 2000
Runs on-premises, virtual, or cloud as needed.
Anti-BEC layer trails API-first leaders.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Sophos Email
Email folded into the Sophos Central single console.
- Best for
- Best for Sophos Central customers
- $$
- roughly $3 to $6 per user per month
- Company
- Abingdon, UK · est. 1985
Links email threats to the endpoint they hit.
Value comes from the Central bundle, not standalone.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Check Point Harmony Email & Collaboration
Inline API that blocks threats before delivery.
- Best for
- Best for pre-delivery inline API blocking
- $$
- roughly $4 to $8 per user per month
- Company
- Tel Aviv, Israel · est. 1993
Blocks before delivery, so fewer threats land.
Inline setup needs care; reporting lags leaders.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Sublime SecurityWildcard
Open detection-as-code with a real free tier.
- Best for
- Best for detection-as-code control
- $
- free community tier, paid plans custom
- Company
- Washington, D.C., USA · est. 2020
Custom detection rules you can write and share.
Rewards SOC skill; less turnkey for lean teams.
Risk signals · none found›
No material public risk signals as of 2026-07-04.
Go deeper
Best pick for your situationmatched by problem
Best for Business Email Compromise
Abnormal Security (#1, 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, 9.0/9.4). Full gateway plus DLP and encryption for regulated firms. It also handles Data Loss.
Best for Phishing
Mimecast (#3, 8.9/9.4). Security bundled with archiving and outage continuity. It also handles Mail Continuity.
Buyer's guide2 questions
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
- 1If 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.
- 2If you are regulated and need data loss prevention, encryption, and archiving in one audited stack, choose Proofpoint or Mimecast.
- 3If 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.
- 4If you have a real SOC and want to control detection logic, Sublime Security lets you write and share your own rules.
Frequently asked5 answers
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.
How this was scored
Every entry is scored on a 9.4-point scale across 6 weighted criteria, reviewed quarterly. 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. Re-scored every 90 days.
- 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.
Changelog2 edits
Wildcard policy change: the #11 wildcard is now unrated. It is selected and explained by the wildcard signal model (wildcard-v2.0), which answers a different question from the scored rubric, so a score would be misleading. The ten ranked entries are unaffected.
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%).
The gripe box
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[Abnormal Security vs Proofpoint vs Mimecast: 11 Best Email Security Software 2026](https://topelevens.com/email-security-software). Top 11, AI-native independent ranking. Methodology public at https://topelevens.com/methodology.Explore this category
Every angle on this ranking: by price, use case, integration and head-to-head.
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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
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