# Best Email Security Solutions for Business (2026)

Compare 7 email security solutions, like Proofpoint, Microsoft Defender for Office 365 and Mimecast, on phishing, BEC and malware protection and tuning effort.

We pick every solution on this list [on merit](https://cybersectools.com/methodology#shortlist-order). Featured vendors that made the list are shown first.

Source: https://cybersectools.com/shortlists/best-email-security-platforms
Updated: 2026-11-01
Edition: Fall 2026.
Reviewed by Nika (Nikoloz) Kokhreidze, CybersecTools.

## Executive summary

As of November 2026, CybersecTools tracks 104 companies that sell email & messaging security solutions as their main business. Email Security Platforms is part of that family. The largest groups are based in the United States, the United Kingdom and Canada. In the last 12 months they raised $69M across 6 funding rounds, 2 companies were acquired and 13 new companies started in the last two years.

From that field we chose seven solutions that stop phishing, business email compromise and malware before they reach your staff. Proofpoint Core Email Protection suits large companies that want deep filtering, one-click removal of bad mail and reports on who gets attacked most. Microsoft Defender for Office 365 fits teams on Microsoft 365, because it works inside the mail system they already run and may come with their license. Mimecast suits companies that want a full gateway with clear message tracking and quarantine.

The main choice is between a gateway and an API product. Gateways such as Proofpoint, Mimecast, Broadcom Symantec and FortiMail sit in front of your mail and filter it before delivery. API products such as Abnormal connect to Microsoft 365 or Google Workspace and judge each message by how people normally write. Many teams now run one of each.

Ask each vendor how much tuning it needs to keep false positives down, because that effort decides your daily workload.

## How we evaluated

We looked at 120 email security platforms solutions from 81 companies, and the 7 on this page made the cut. We combined our judgment from years of leading enterprise security programs with market data from [Mandos](https://mandos.io/data/companies?utm_source=cybersectools.com&utm_medium=shortlist), our market intelligence platform, and with the vendor and review pages listed under Sources at the end of this page. For customer feedback, we left out paid reviews, reviews by vendor staff or partners, review campaigns and anything older than two years, so you get an accurate view of what customers say.

Four traits mattered most: catching phishing and payment fraud with few false positives; protection for Microsoft 365 and Google Workspace; removing bad mail after delivery; and links to your SIEM and SOAR. We left out DMARC-only products, mail servers and managed resale services. The order follows how widely each product is used by teams like yours. Company momentum shows how the vendor itself is growing, so a market leader can rank first with a lower score.

Read the full method: https://cybersectools.com/methodology#why

## What is Email Security Platforms

Email security products protect your mail from phishing, business email compromise, malware and spam. Some sit in front of your mail as a gateway and filter every message before delivery. Others connect to Microsoft 365 or Google Workspace through an API, watch messages inside the mailbox and pull out threats after delivery.

This matters because email is still the most common way attacks start. One convincing message can lead to stolen logins, a fake payment or ransomware. Email security catches most of these before a person has to decide, and it lets your team remove a bad message from every mailbox at once.

### Compare Email Security Platforms solutions

This analysis focuses on seven email security solutions. The table compares them on vendor, who each one is best for, deployment model and the NIST CSF functions they cover.

| # | Solution | Best for | Starting price | Deployment | Company size | NIST CSF functions |
| --- | --- | --- | --- | --- | --- | --- |
| 1 | [Proofpoint Core Email Protection](https://cybersectools.com/tools/proofpoint-threat-protection) | Large companies wanting deep email filtering | Contact sales | Cloud | SMB to Enterprise | Protect, Detect |
| 2 | [Microsoft Defender for Office 365](https://cybersectools.com/tools/microsoft-defender-for-office-365) | Teams running Microsoft 365 | From $2 per user per month | Cloud | SMB to Enterprise | Protect, Detect, Respond |
| 3 | [Mimecast Advanced Email Security](https://cybersectools.com/tools/mimecast-advanced-email-security) | Companies wanting a full gateway with clear tracking | Contact sales | Hybrid | SMB to Enterprise | Protect, Detect |
| 4 | [Abnormal Inbound Email Security](https://cybersectools.com/tools/abnormal-security-cloud-email-security) | Microsoft 365 or Google teams fighting BEC | Contact sales | Cloud | SMB to Enterprise | Detect |
| 5 | [Cisco Secure Email Threat Defense](https://cybersectools.com/tools/cisco-secure-email-threat-defense) | Cisco shops wanting Talos-backed filtering | Contact sales | Cloud | SMB to Enterprise | Detect, Respond |
| 6 | [Broadcom Symantec Email Security](https://cybersectools.com/tools/broadcom-symantec-email-security) | Large companies needing cloud and on-premises mail | Contact sales | Hybrid | SMB to Enterprise | Protect, Detect, Respond |
| 7 | [Fortinet FortiMail Email and Workspace Security](https://cybersectools.com/tools/fortinet-fortimail-email-security) | Fortinet customers and on-premises mail servers | Contact sales | Hybrid | SMB to Enterprise | Protect, Detect |

Vendors change prices, so check before you buy.

**See every Email Security Platforms solution we list**

The full Email Security Platforms market, filtered by company size, deployment and NIST coverage.

[Browse Email Security Platforms solutions →](https://cybersectools.com/categories/email-security-platforms)

### 1. Proofpoint Core Email Protection

**[Proofpoint](https://mandos.io/data/companies/proofpoint?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. Email security platform with AI-based threat detection and DLP capabilities

Sunnyvale, United States · Founded 2002 · $86M raised · Momentum 57/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP, PCI DSS, FIPS 140, CSA STAR

**Best for:** Large companies wanting deep email filtering

Product page: https://cybersectools.com/tools/proofpoint-threat-protection

#### At a glance

- Vendor: Proofpoint
- Headquarters: Sunnyvale, United States
- Founded: 2002
- Deployment: Cloud
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Protect, Detect
- Pricing: Contact sales

#### Our take

Proofpoint Core Email Protection uses AI to detect phishing, business email compromise and malware, and it adds account takeover protection and email fraud defense. The wider Proofpoint platform adds email DLP, encryption, archiving and security awareness training, so many large companies buy several parts together.

It protects Microsoft 365 and Google Workspace and can pull bad mail out of every mailbox after delivery.

It earns a place because it goes past filtering into DLP, encryption, archiving and fraud defense from one vendor, which suits a large company that wants to run email security as one program. Archiving and supervision for SEC and FINRA rules matter if you work in financial services. Weigh which parts you really need, because the whole platform is a bigger commitment than a filter.

#### Proofpoint Core Email Protection main features

- AI-based email threat detection and prevention
- Phishing and business email compromise protection
- Adaptive email DLP with machine learning
- Email encryption with policy-based controls
- Account takeover protection
- CASB for cloud application security
- Email fraud defense and DMARC compliance
- Insider threat management

#### Proofpoint Core Email Protection main integrations

Microsoft 365, Google Workspace

#### Before you buy

Where it is strong:

- Strong filtering of spam, phishing and fraud
- One-click removal of bad mail from every mailbox
- Reports on the people attacked most often

Ask in the demo:

- List which Proofpoint modules you need and price them together
- Ask how much tuning a typical rollout needs
- Check how it works alongside Microsoft 365's own filtering

### 2. Microsoft Defender for Office 365

**[Microsoft](https://mandos.io/data/companies/microsoft?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. Email and collaboration security for Microsoft 365 environments

Redmond, United States · Founded 1975 · Public company · Momentum 59/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP, PCI DSS, HIPAA

**Best for:** Teams running Microsoft 365

Product page: https://cybersectools.com/tools/microsoft-defender-for-office-365

#### At a glance

- Vendor: Microsoft
- Headquarters: Redmond, United States
- Founded: 1975
- Ownership: Public company (MSFT)
- Deployment: Cloud
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Protect, Detect, Respond
- Starting price: From $2 per user per month

#### Our take

Microsoft Defender for Office 365 protects mail and collaboration inside Microsoft 365. It checks links and attachments in real time, including QR codes, uses AI to spot business email compromise and scams, and can investigate and remediate threats automatically.

It covers mail as well as Teams, SharePoint and OneDrive, and it can disable compromised users and remove bad mail after delivery.

It is on the list because it is built into Microsoft 365, and many companies already own it through their license, so the buying question is often settled before you start. That makes it the natural first layer if you run Microsoft 365. Decide whether it covers your risk alone or needs a second product beside it, since it is built to work with other email security products.

#### Microsoft Defender for Office 365 main features

- AI-powered sentiment analysis
- Inline user protection
- BEC attack disruption
- Security posture optimization
- Priority account support
- Awareness and training
- Investigation and hunting
- Automated response and remediation

#### Microsoft Defender for Office 365 main integrations

Darktrace /EMAIL, KnowBe4 Defend, Proofpoint Core Email Protection, VIPRE Integrated Email Security

#### What customers say

Sentiment: 83% positive · 11% mixed · 6% negative (from first-hand public reviews and comments, 2025 to 2026).
Most praised: Speed, Integrations.
Most criticized: False positives, Setup.

Defender for Office 365 runs inside Microsoft 365, so teams protect mail, Teams and OneDrive without buying a separate email gateway. Customers credit Safe Links and Safe Attachments with stopping phishing before users click, and the automatic investigation cuts the manual work after an alert. The catch is tuning, because the policies take time to set up and safe mail sometimes gets flagged, so someone has to review it by hand. Some also find that phishing and spam still slip through at times.

#### Before you buy

Where it is strong:

- Built into Microsoft 365, no extra gateway
- Real-time checks on links, attachments and QR codes
- Automatic investigation and remediation

Ask in the demo:

- Check whether your license includes Plan 1 or Plan 2
- Plan who will own policy tuning
- Test detection of business email compromise in a pilot

### 3. Mimecast Advanced Email Security

**[Mimecast](https://mandos.io/data/companies/mimecast?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. Email security platform protecting M365 & Google Workspace from threats

London, United Kingdom · Founded 2003 · $90M raised · Momentum 54/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP, PCI DSS, HIPAA, TISAX

**Best for:** Companies wanting a full gateway with clear tracking

Product page: https://cybersectools.com/tools/mimecast-advanced-email-security

#### At a glance

- Vendor: Mimecast
- Headquarters: London, United Kingdom
- Founded: 2003
- Deployment: Hybrid
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Protect, Detect
- Starting price: Contact sales

#### Our take

Mimecast Advanced Email Security combines machine learning, social graphing and sandboxing to block phishing, impersonation and malware. It rewrites links to check them at click time, spots QR code phishing and uses computer vision to catch brand impersonation.

It protects Microsoft 365, Google Workspace and on-premises mail, and it connects to CrowdStrike, Netskope, Palo Alto Networks XSOAR, Cybereason, Datadog and Jira.

It earns its place because you can run it as a gateway or through an API, and archiving and continuity sit in the same platform, which suits a company with a mixed mail setup. Social graphing and computer vision aim at impersonation, not only malware. Weigh whether you need the archive and continuity parts, since they change how much of your mail flow depends on one vendor.

#### Mimecast Advanced Email Security main features

- AI and machine learning-based threat detection
- Social graphing for anomaly detection
- Sandboxing for malware analysis
- URL on-click protection
- Computer vision for brand impersonation detection
- Contextual email banners for risk assessment
- QR code phishing detection
- Business email compromise protection

#### Mimecast Advanced Email Security main integrations

Microsoft 365, Google Workspace, CrowdStrike, Netskope, Palo Alto Networks XSOAR, Axonius, Code42, Cybereason, Graylog, Gurucul, Hunters, Intezer, Jira, BambooHR, Box, Cribl, Cyware, Datadog, Fortinet, Webex, Devo, Duo, Elastic, Exabeam, LogRhythm, Logpoint, XM Cyber, Anomali, CyberArk, D3 Security, Arctic Wolf

#### What customers say

Sentiment: 85% positive · 15% mixed · 0% negative (from first-hand public reviews and comments, 2025 to 2026).
Most praised: Speed, Ease of use, Reports.
Most criticized: Interface, Setup.

Customers rely on it to stop phishing, spam and malware before mail reaches the inbox, and several single out how it catches impersonation emails and harmful links. Admins also like message tracking, because they can trace where a message went when something is questioned. The catch is the admin side, since the console takes time to learn and setup can feel clunky.

#### Before you buy

Where it is strong:

- Clear message tracking and quarantine
- Link checks at click time and QR code detection
- Wide set of security product connections

Ask in the demo:

- Ask how long admins usually take to learn the console
- Check which features each package includes
- Test false positive rates on your own mail

### 4. Abnormal Inbound Email Security

**[Abnormal Security](https://mandos.io/data/companies/abnormal-security?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. AI-powered email security platform detecting advanced threats via behavioral analysis

San Francisco, United States · Founded 2018 · $534M raised · Momentum 71/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP

**Best for:** Microsoft 365 or Google teams fighting BEC

Product page: https://cybersectools.com/tools/abnormal-security-cloud-email-security

#### At a glance

- Vendor: Abnormal Security
- Headquarters: San Francisco, United States
- Founded: 2018
- Deployment: Cloud
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Detect
- Pricing: Contact sales

#### Our take

Abnormal Inbound Email Security connects to Microsoft 365 or Google Workspace through an API in one click, with no change to mail routing. It learns who normally writes to whom and how, then flags messages that break the pattern. That helps catch payment and vendor fraud that contain no links or malware.

It removes malicious mail automatically and explains each verdict with evidence. It connects to Microsoft Sentinel, Splunk, QRadar, Rapid7, Cortex XSOAR and Torq.

It belongs here as the API option, because it judges each message against normal behavior and needs no rules to maintain. That suits you if vendor and payment fraud worry you more than mass malware. Since it does not sit in the mail path, decide whether you pair it with a gateway or with the filtering your mail platform already has.

#### Abnormal Inbound Email Security main features

- Behavioral AI analyzing identity, behavior, and content signals across email and SaaS platforms
- One-click API integration for deployment without inline configuration
- Automated detection and remediation of malicious emails to reduce SOC workload
- Business email compromise (BEC) detection through sender relationship and communication history analysis
- Vendor email compromise (VEC) detection monitoring partner behavior and flagging anomalies
- Explainable outcomes with contextual evidence and behavioral metadata for every threat
- Customizable risk thresholds, remediation actions, and quarantine workflows
- Unified console consolidating Microsoft and Abnormal detections for centralized management

#### Abnormal Inbound Email Security main integrations

Microsoft 365, Google Workspace, Microsoft Sentinel, Splunk, QRadar, Rapid7, Splunk SOAR, Cortex XSOAR, Torq

#### Before you buy

Where it is strong:

- Behavioral detection of payment and vendor fraud
- API setup with no mail routing changes
- Automatic removal with explained verdicts

Ask in the demo:

- Ask how it works alongside your existing gateway
- Run a trial on your own mailboxes to compare catches
- Check pricing per mailbox at your size

**Alternatives to each solution on this list**

The closest Email Security Platforms alternatives for every pick, matched on features and integrations.

[See Email Security Platforms alternatives →](https://cybersectools.com/alternatives)

### 5. Cisco Secure Email Threat Defense

**[Cisco](https://mandos.io/data/companies/cisco?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. Email threat protection for Microsoft 365 with advanced detection capabilities

San Jose, United States · Founded 1984 · Public company · Momentum 59/100 (Mandos)

Certifications: SOC 2, ISO 27001, PCI DSS

**Best for:** Cisco shops wanting Talos-backed filtering

Product page: https://cybersectools.com/tools/cisco-secure-email-threat-defense

#### At a glance

- Vendor: Cisco
- Headquarters: San Jose, United States
- Founded: 1984
- Ownership: Public company (CSCO)
- Deployment: Cloud
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Detect, Respond
- Pricing: Contact sales

#### Our take

Cisco Secure Email Threat Defense uses AI, natural language models and several detection engines backed by Cisco's Talos threat intelligence. It sorts threats by the part of the company they target and keeps searchable telemetry for investigations.

It can run as an API product for Microsoft 365 or, in its higher tier, add an inline gateway, both from one console.

It is on the list as a Microsoft 365 product that can grow with you: you start in API mode and add the inline gateway later, from the same console. That suits a team that already runs Cisco security. Check fit first if you run Google Workspace or your own mail servers, because the product is built for Microsoft 365.

#### Cisco Secure Email Threat Defense main features

- AI and machine learning threat detection
- Natural language processing models
- Multiple parallel detection engines
- Malicious technique identification
- Searchable threat telemetry
- Threat categorization by targeted part of the organization
- Talos threat intelligence
- Pre-delivery threat protection

#### Cisco Secure Email Threat Defense main integrations

Microsoft 365

#### What customers say

Sentiment: 72% positive · 28% mixed · 0% negative (from first-hand public reviews and comments, 2024 to 2026).
Most praised: Speed.

The threat intelligence behind it is what customers trust most, because it lets the product spot phishing, malware attachments and bad links and stop them before they reach inboxes. Teams also find it easy to manage, and they can tune the filtering rules to fit how their own company handles email.

#### Before you buy

Where it is strong:

- Talos threat intelligence behind detection
- API and gateway options in one console
- Fine-grained rules for each message

Ask in the demo:

- Ask which tier includes the gateway
- Check support coverage for your region
- Plan time for regular tuning

### 6. Broadcom Symantec Email Security

**[Broadcom](https://mandos.io/data/companies/broadcom?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. Enterprise email security platform for cloud and on-premise deployments

Palo Alto, United States · Founded 1991 · Public company · Momentum 54/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP, PCI DSS

**Best for:** Large companies needing cloud and on-premises mail

Product page: https://cybersectools.com/tools/broadcom-symantec-email-security

#### At a glance

- Vendor: Broadcom
- Headquarters: Palo Alto, United States
- Founded: 1991
- Ownership: Public company (AVGO)
- Deployment: Hybrid
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Protect, Detect, Respond
- Pricing: Contact sales

#### Our take

Broadcom Symantec Email Security protects against ransomware, spear phishing and business email compromise in the cloud or on premises. It adds sandboxing, click-time URL checks, browser isolation for risky links and clawback of bad mail from Office 365.

It also watches outbound mail for sensitive data and supports Microsoft 365 and Google Workspace.

It makes the list because it offers both a cloud service and an on-premises Messaging Gateway, as a virtual or physical appliance, which suits large companies that still run their own mail servers. Browser isolation opens risky links away from the user's machine. If you plan to move mail to the cloud, ask how your policies carry over from the gateway to the cloud service.

#### Broadcom Symantec Email Security main features

- Multilayered defense against ransomware, spear phishing, and BEC attacks
- Cloud-based and on-premises deployment options
- Cloud-based sandboxing for advanced threat detection
- Click-time URL protection
- Office 365 clawback and remediation
- Web browser isolation
- Outbound email monitoring and data protection
- Sender authentication

#### Broadcom Symantec Email Security main integrations

Microsoft 365, Google Workspace

#### Before you buy

Where it is strong:

- Cloud and on-premises deployment
- Browser isolation for risky links
- Clawback of delivered threats

Ask in the demo:

- Ask about Broadcom's support model and renewal terms
- Check which features each license tier includes
- Test clawback speed in a pilot

### 7. Fortinet FortiMail Email and Workspace Security

**[Fortinet](https://mandos.io/data/companies/fortinet?utm_source=cybersectools.com&utm_medium=shortlist-md&utm_campaign=explore-in-mandos)**. AI-powered email security platform protecting against phishing, BEC, and ATO

Sunnyvale, United States · Founded 2000 · Public company · Momentum 75/100 (Mandos)

Certifications: SOC 2, ISO 27001, FedRAMP, PCI DSS, HIPAA

**Best for:** Fortinet customers and on-premises mail servers

Product page: https://cybersectools.com/tools/fortinet-fortimail-email-security

#### At a glance

- Vendor: Fortinet
- Headquarters: Sunnyvale, United States
- Founded: 2000
- Ownership: Public company (FTNT)
- Deployment: Hybrid
- Company size: SMB, Mid-Market, Enterprise
- NIST CSF: Protect, Detect
- Pricing: Contact sales

#### Our take

Fortinet FortiMail protects inbound and outbound mail with AI detection engines and real-time threat intelligence, and it adds data loss prevention and outbound encryption. It runs as a gateway or through an API for Microsoft 365 and Google Workspace, and it supports multiple tenants for service providers.

It links to FortiSandbox, FortiSIEM and FortiSOAR through the Fortinet Security Fabric.

It belongs here because inbound and outbound protection, DLP and encryption come in one product that runs as a gateway or through an API, which suits companies that still host their own mail servers. Multi-tenancy and a managed incident response service help if a provider runs your email security. If you use no other Fortinet products, weigh how much of its value depends on that ecosystem.

#### Fortinet FortiMail Email and Workspace Security main features

- AI-powered email threat protection
- Next-generation detection engines
- Inbound email protection
- Outbound email protection
- Data loss prevention and outbound encryption
- Real-time email threat intelligence
- Early threat detection through pattern recognition
- Managed incident response service

#### Fortinet FortiMail Email and Workspace Security main integrations

Microsoft 365, Google Workspace, Exchange Online

#### What customers say

Sentiment: 64% positive · 36% mixed · 0% negative (from first-hand public reviews and comments, 2024 to 2026).
Most praised: Ease of use, Integrations.
Most criticized: Reports, Interface.

FortiMail sits in front of the mail server as a gateway, and customers say it stops spam, phishing and malware well, which makes bad mail quicker to deal with. Admins find it simple to run day to day, and it connects easily with other security products, so teams already on Fortinet can manage it alongside the rest.

#### Before you buy

Where it is strong:

- Inbound and outbound protection with DLP
- Gateway or API deployment
- Fits other Fortinet products

Ask in the demo:

- Ask whether you need the gateway, the API option or both
- Plan setup time if your team is new to mail flow
- Check bundle pricing with your Fortinet contracts

## How they fit your cybersecurity program (NIST CSF)

NIST CSF 2.0 has six functions: Govern, Identify, Protect, Detect, Respond and Recover. The grid shows which functions each pick maps to in our record, so you can see where a solution sits in your program and what it leaves to other controls.

All 7 solutions map to Detect. 5 of 7 map to Protect. 3 of 7 map to Respond. None map to Govern, Identify or Recover.

| Solution | Govern | Identify | Protect | Detect | Respond | Recover |
| --- | --- | --- | --- | --- | --- | --- |
| All solutions on this list | 0 of 7 | 0 of 7 | 5 of 7 | 7 of 7 | 3 of 7 | 0 of 7 |
| Proofpoint Core Email Protection | – | – | 3 of 5 (Identity Management, Authentication, and Access Control, Awareness and Training, Data Security) | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | – | – |
| Microsoft Defender for Office 365 | – | – | 1 of 5 (Awareness and Training) | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | 2 of 4 (Incident Management, Incident Mitigation) | – |
| Mimecast Advanced Email Security | – | – | 1 of 5 (Data Security) | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | – | – |
| Abnormal Inbound Email Security | – | – | – | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | – | – |
| Cisco Secure Email Threat Defense | – | – | – | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | 1 of 4 (Incident Mitigation) | – |
| Broadcom Symantec Email Security | – | – | 2 of 5 (Awareness and Training, Data Security) | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | 1 of 4 (Incident Mitigation) | – |
| Fortinet FortiMail Email and Workspace Security | – | – | 1 of 5 (Data Security) | 2 of 2 (Continuous Monitoring, Adverse Event Analysis) | – | – |

Each cell shows how many of the function's NIST CSF 2.0 categories the solution maps to, with the category names.

A product helps you reach these outcomes, but it does not make you compliant on its own. Your people and processes do the rest.

## CISO checklist for selecting an Email Security Platforms product

Work through these steps in order to go from inbox risk to a contract you can defend.

1. **Check what your Microsoft 365 or Google plan already blocks.** You may already own part of the protection.
2. **Decide between a gateway, an API product or both.** Each catches different threats and changes mail flow differently.
3. **Run a pilot on your own mailboxes.** Real mail shows catches and misses better than a demo.
4. **Count false positives during the pilot.** Blocked real mail costs time and trust.
5. **Test removing a delivered message from every mailbox.** Fast removal limits damage when a threat slips through.
6. **Ask how payment and vendor fraud are detected.** These messages often contain no links or malware.
7. **Confirm how alerts reach your SIEM and SOAR.** Email threats are often the start of larger incidents.
8. **Plan who will own policy tuning.** Tuning effort is the most common complaint in this category.
9. **Price the full bundle for your user count.** Advanced features are often sold in higher tiers.

**Compare Email Security Platforms solutions side by side**

Features, integrations, NIST coverage and deployment for every Email Security Platforms solution we list, in one table.

[Compare Email Security Platforms solutions →](https://cybersectools.com/compare)

## Other solutions we considered for this shortlist

We looked at 76 products for this list. These did not make the 7 above but are worth a look for the right team.

1. [RavenMail](https://cybersectools.com/tools/ravenmail)
   Cloud-native AI email security platform with LLM-based threat detection and DLP.
2. [Cloudflare Cloud Email Security](https://cybersectools.com/tools/cloudflare-cloud-email-security) · Cloudflare, Inc.
   Cloudflare Cloud Email Security is a cloud-based email protection service that safeguards organizations against phishing, malware, spam, and other email-borne threats through integrated threat detection and prevention capabilities.
3. [OpenText Email Security](https://cybersectools.com/tools/opentext-email-security) · OpenText Cybersecurity
   Comprehensive email security platform protecting inbound/outbound communications
4. [Trend Micro Trend Vision One™](https://cybersectools.com/tools/trend-micro-trend-vision-onetm) · Trend Micro
   AI-powered email and collaboration security platform for threat detection
5. [Darktrace Email Security](https://cybersectools.com/tools/darktrace-email-security) · Darktrace
   AI-powered email security platform detecting threats across email and messaging
6. [Kaseya 365 Advanced Threat Protection](https://cybersectools.com/tools/kaseya-365-advanced-threat-protection) · Kaseya
   ATP solution for SaaS & email with AI-driven detection & auto-response
7. [KnowBe4 Cloud Email Security](https://cybersectools.com/tools/knowbe4-cloud-email-security) · KnowBe4
   AI-driven email security platform for Microsoft 365 inbound/outbound threats
8. [ESET Mail Security](https://cybersectools.com/tools/eset-mail-security) · ESET
   Email security for Microsoft Exchange servers with anti-spam and anti-malware
9. [Sophos Email](https://cybersectools.com/tools/sophos-email) · Sophos
   Email security platform with phishing/BEC protection and MDR/XDR integration

Explore all Email Security Platforms solutions: https://cybersectools.com/categories/email-security-platforms

## Conclusion

Start with your mail platform and your biggest risk. If you run Microsoft 365, Defender for Office 365 may already be in your license, and Abnormal adds behavior-based fraud detection on top. If you want a full gateway, Proofpoint and Mimecast are long-time leaders, and Broadcom Symantec suits mixed cloud and on-premises mail.

Cisco fits teams that already rely on Cisco and Talos, and FortiMail suits Fortinet customers and companies running their own mail servers.

## Frequently Asked Questions

### Is Microsoft 365's built-in filtering enough?

It blocks a lot of spam and known malware, and Defender for Office 365 adds stronger phishing protection. Many companies still add another product to catch targeted phishing and payment fraud, so test against your own mail.

### What is the difference between a secure email gateway and API email security?

A gateway sits in front of your mail and filters each message before delivery, which needs a change to mail routing. API products connect to the mailbox and can remove threats after delivery, with no routing change.

### What is business email compromise?

Business email compromise is fraud where an attacker pretends to be a boss, colleague or supplier to get a payment or data. These messages often have no links or malware, so behavior-based detection helps catch them.

### Can email security remove a message after it was delivered?

Yes. Most products here can pull a bad message out of every mailbox at once, which matters when a threat is found after delivery.

### Do I need DMARC as well?

Yes, DMARC is a separate job. It stops others from sending mail that pretends to come from your own domain, while email security protects the mail your staff receive.

## Sources

These are the pages we reviewed for each pick: the vendor's own product page and website, its market data on Mandos, and every review page we read for customer feedback.

1. **Proofpoint Core Email Protection** · Proofpoint: [Product page](https://www.proofpoint.com/us/products/email-protection) · [Proofpoint website](https://www.proofpoint.com/) · [Market data on Mandos](https://mandos.io/data/companies/proofpoint?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [G2](https://www.g2.com/products/proofpoint-core-email-protection/reviews) · [PeerSpot](https://www.peerspot.com/products/proofpoint-email-protection-reviews) · [Reddit: proofpoint isnt cutting it whats better](https://www.reddit.com/r/msp/comments/1pbpf7q/proofpoint_isnt_cutting_it_whats_better/) · [Reddit: mimecast proofpoint rough cost](https://www.reddit.com/r/sysadmin/comments/izu97k/mimecast_proofpoint_rough_cost/) · [Reddit: spamtitan vs proofpoint essentials beginner vs](https://www.reddit.com/r/msp/comments/we0hmo/spamtitan_vs_proofpoint_essentials_beginner_vs/)
2. **Microsoft Defender for Office 365** · Microsoft: [Product page](https://www.microsoft.com/en-us/security/business/siem-and-xdr/microsoft-defender-office-365/) · [Microsoft website](https://www.microsoft.com/) · [Market data on Mandos](https://mandos.io/data/companies/microsoft?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [G2](https://www.g2.com/products/microsoft-microsoft-defender-for-office-365/reviews) · [Gartner Peer Insights](https://www.gartner.com/reviews/product/microsoft-defender-for-office-365) · [PeerSpot](https://www.peerspot.com/products/microsoft-defender-for-office-365-reviews) · [Reddit: is defender for office bad](https://www.reddit.com/r/DefenderATP/comments/1fsr7z2/is_defender_for_office_bad/) · [Reddit: what is your experience with defender for office](https://www.reddit.com/r/sysadmin/comments/17eng89/what_is_your_experience_with_defender_for_office/) · [Reddit: your thoughts on ms defender for office 365 plan 2](https://www.reddit.com/r/Office365/comments/1bfe0yk/your_thoughts_on_ms_defender_for_office_365_plan_2/) · [Reddit: defender for office 365 business premium are we](https://www.reddit.com/r/msp/comments/1t3h84g/defender_for_office_365_business_premium_are_we/)
3. **Mimecast Advanced Email Security** · Mimecast: [Product page](https://www.mimecast.com/products/email-security/) · [Mimecast website](https://www.mimecast.com/) · [Market data on Mandos](https://mandos.io/data/companies/mimecast?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [Gartner Peer Insights](https://www.gartner.com/reviews/product/mimecast-advanced-email-security) · [PeerSpot](https://www.peerspot.com/products/mimecast-advanced-email-security-reviews) · [G2](https://www.g2.com/products/mimecast-advanced-email-security/reviews) · [Reddit: email security and archiving](https://www.reddit.com/r/paloaltonetworks/comments/1owbnyr/email_security_and_archiving/) · [Reddit: suggestions for email security for 365](https://www.reddit.com/r/msp/comments/y7xesd/suggestions_for_email_security_for_365/)
4. **Abnormal Inbound Email Security** · Abnormal Security: [Product page](https://abnormal.ai/platform/inbound-email-security) · [Abnormal Security website](https://abnormal.ai/) · [Market data on Mandos](https://mandos.io/data/companies/abnormal-security?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [PeerSpot](https://www.peerspot.com/products/abnormal-security-reviews)
5. **Cisco Secure Email Threat Defense** · Cisco: [Product page](https://www.cisco.com/site/us/en/products/security/secure-email/index.html) · [Cisco website](https://www.cisco.com/) · [Market data on Mandos](https://mandos.io/data/companies/cisco?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [Gartner Peer Insights](https://www.gartner.com/reviews/product/cisco-secure-email-threat-defense) · [Reddit: cisco esa](https://www.reddit.com/r/networking/comments/1n7w62j/cisco_esa/) · [Reddit: need help cisco email threat defense](https://www.reddit.com/r/Cisco/comments/1golz1u/need_help_cisco_email_threat_defense/) · [G2](https://www.g2.com/products/cisco-secure-email-threat-defense/reviews)
6. **Broadcom Symantec Email Security** · Broadcom: [Product page](https://www.broadcom.com/products/cybersecurity/email/) · [Broadcom website](https://www.broadcom.com/) · [Market data on Mandos](https://mandos.io/data/companies/broadcom?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [G2](https://www.g2.com/products/symantec-email-security-cloud/reviews) · [Gartner Peer Insights](https://www.gartner.com/reviews/product/symantec-email-security-cloud) · [Reddit: migration to symantec email security cloud from](https://www.reddit.com/r/exchangeserver/comments/18c10z9/migration_to_symantec_email_security_cloud_from/) · [Reddit: getting rid of symantec email securitycloud](https://www.reddit.com/r/sysadmin/comments/iyicr2/getting_rid_of_symantec_email_securitycloud/) · [Reddit: psa to anyone using symantecs emailsecurity cloud](https://www.reddit.com/r/sysadmin/comments/yae2s8/psa_to_anyone_using_symantecs_emailsecurity_cloud/)
7. **Fortinet FortiMail Email and Workspace Security** · Fortinet: [Product page](https://www.fortinet.com/products/email-security) · [Fortinet website](https://www.fortinet.com/) · [Market data on Mandos](https://mandos.io/data/companies/fortinet?utm_source=cybersectools.com&utm_medium=shortlist-md-sources&utm_campaign=explore-in-mandos) · [Gartner Peer Insights](https://www.gartner.com/reviews/product/fortimail) · [PeerSpot](https://www.peerspot.com/products/fortinet-fortimail-reviews) · [G2](https://www.g2.com/products/fortimail/reviews)

---

For AI agents: every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md.

More on the vendors on this list: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=shortlist-md