Email Security Tools Compared

Email security tools protect against phishing, business email compromise (BEC), malicious attachments, and account takeover via SEGs or API-integrated platforms. Side-by-side comparison across 4 tools — descriptive only, no recommendations.

6 min read Data verified: July 2026 4 tools compared

Proofpoint

Email Security / SEG

Paid

$2-$5/user/mo (Essentials), $5-$15/user/mo (Enterprise tiers with TAP) large deployments $100K+/yr

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Abnormal Security

Email Security (Behavioral AI)

Paid

~$150-$200/user/yr typical enterprise pricing per practitioner reports custom quoting; ~$174/user/yr cited as common reference point

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Mimecast

Email Security / SEG

Paid

Estimated $5-$15/user/mo across Critical, Advanced, Premium tiers new email security plans introduced 2026 with custom pricing

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MailScanner

Email Security (Open Source)

Free / OSS

Free (GPL); paid commercial support contracts available through MailScanner… sponsors and integrators

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Comparing →

Proofpoint

Email Security / SEG

Abnormal Security

Email Security (Behavioral AI)

Mimecast

Email Security / SEG

MailScanner

Email Security (Open Source)

$ Pricing & plans

5 dimensions

Pricing model

Essentials tier: ~$2-$5/user/mo ($36-$60/user/yr)

Business, Advanced, Professional sub-tiers. Enterprise with TAP: ~$5-$15/user/mo depending on modules. Large enterprise bundles (Threat Protection + DLP + Insider Threat + Compliance) can exceed $100K/yr.

Custom enterprise pricing

Vendr/CostBench data references ~$174/user/yr as a common reference point; pricing scales with employee count and modules selected

Custom quote-based

estimated $5-$15/user/mo. UK G-Cloud framework data shows mid-tier pricing in similar ranges. Module additions (archiving +30-40%, training +$1.50/user, DLP +20-30%) stack above base tier. 500-user org might pay ~$3/user/mo while 100-user org pays $4+/user/mo at same modules.

MailScanner software is free under GPL.

Optional commercial support contracts and managed deployments via MailScanner sponsors and integrators (e.g., Baruwa Enterprise, MailWatch ecosystem). Most deployments run fully self-supported.

Pricing tier

Paid

Free / OSS

Free tier / trial

Trial only

Free trials available for Essentials plans via Proofpoint sales or authorized partners; enterprise PoC via direct sales

Trial only

No free tier; risk assessment scan via API integration available for evaluation; trial/PoC via direct sales

Trial only

No free plan; trials available upon request via Mimecast sales

Free tier

Software permanently free; no trial needed

Volume discounts

Tiered pricing with breaks at 100, 500, 1000+ users

multi-year commitments common; bundling additional modules increases discount leverage

Negotiated by employee count

multi-year commitments common; VIP protection module sometimes bundled into base contract for larger deals

Volume tiers with significant per-user variance

500+ user deployments commonly see better per-user pricing than 100-user deployments; multi-year commitments offer 10-20% savings on bundles

Not applicable for free software

Hidden costs

Targeted Attack Protection (TAP), DLP, Insider Threat Management, Archiving,…

Security Awareness Training, and Email Fraud Defense (DMARC) are typically priced as separate modules; professional services for setup

VIP Protection (executive monitoring), Supply Chain Fraud Detection (vendor…

email compromise), Advanced Threat Intelligence, AI Security Mailbox, and other add-on modules may carry incremental fees; professional services for custom workflow design

Renewal price increases (25%+ reported in some cases

multi-year terms reduce exposure), data export fees when migrating, premium support charges for SMBs, bundled training and other features charged even if unused

Linux mail server infrastructure, SpamAssassin rule maintenance, optional…

commercial AV engine subscriptions (F-Prot, Sophos), operational labor for tuning and false-positive triage, monitoring/reporting infrastructure

↗ Deployment & integrations

3 dimensions

Deployment

Cloud SEG — MX records point to Proofpoint, which scans inbound/outbound mail…

before delivery; supplemental API integration for some use cases

API-based integration with Microsoft 365 or Google Workspace via three-click connection

no MX record changes, no mail flow disruption

Cloud Secure Email Gateway

MX records redirect mail through Mimecast for scanning and policy enforcement before delivery to Microsoft 365 or Google Workspace; some hybrid/on-prem options for specific use cases

Self-hosted on Linux mail servers

integrates with Postfix, Sendmail, Exim, Qmail, Zmailer as a content scanner; commonly paired with SpamAssassin (spam), ClamAV (malware), and optionally F-Prot, Sophos, or other commercial AV engines

Typical deployment time

Days for Essentials deployments with mail flow cutover

weeks for enterprise with TAP, DLP, archiving, awareness training, and DMARC integration

Minutes for API integration

days to weeks for full tuning, vendor relationship baselining, and workflow integration

Days to weeks for SEG mail flow cutover

weeks to months for full deployments with archiving, continuity, training, and DLP integration

Hours for basic install on existing mail server

days to weeks for production tuning, rule customization, quarantine workflows, and reporting setup

Key integrations

Microsoft 365, Google Workspace, Splunk, Microsoft Sentinel, IBM QRadar,…

CrowdStrike, Okta, ServiceNow; integrates with Proofpoint Security Awareness Training, DLP, and Archiving products

Microsoft 365, Google Workspace

SIEM forwarding (Splunk, Microsoft Sentinel); CrowdStrike, Okta, Slack, ServiceNow; identity and SSO platforms

Microsoft 365, Google Workspace, Microsoft Sentinel, Splunk, CrowdStrike,…

ServiceNow, Okta, Active Directory; 30+ integrations for IAM/PAM, endpoint, SOAR, SIEM

Postfix, Sendmail, Exim, Qmail, Zmailer

SpamAssassin, ClamAV, F-Prot, Sophos, Avira, BitDefender, Kaspersky engines via integration; MailWatch web UI for monitoring; SIEM forwarding via syslog

📧 Email Security-specific evaluation

7 dimensions

Architecture / deployment

Cloud Secure Email Gateway

mail flow is redirected via MX records through Proofpoint before delivery to Microsoft 365 or Google Workspace; supplemental API integration for some products

API-native — connects to Microsoft 365 or Google Workspace via Graph API or equivalent

scans inbound, outbound, and internal email post-delivery for anomalies; quarantines or flags suspicious messages

Cloud Secure Email Gateway

mail routes through Mimecast via MX records before delivery; tightly integrated with Mimecast Cloud Archive and Continuity for unified email management

Content scanner that integrates into Linux mail server mail flow

Postfix/Sendmail/Exim receives mail, hands to MailScanner for scanning, which returns clean mail back to MTA for delivery; deployable as bastion mail gateway in front of internal mail servers

Threat detection approach

Multi-layer detection

signature-based filtering, URL rewriting and sandboxing (TAP), attachment sandboxing, anti-spam scoring, ML-based impostor and BEC detection, Emerging Threats threat intelligence

Behavioral AI analyzing tens of thousands of signals per organization

communication patterns, vendor relationships, language patterns, identity behavior, login signals; no reliance on signatures or static rules

AI-powered threat detection with URL and attachment protection, impersonation…

defense, multi-layer scanning; URL rewriting at click-time; integration with threat intelligence feeds

Multi-engine

SpamAssassin for spam scoring, ClamAV/commercial engines for malware, content filtering for attachments and URLs, custom rule sets via Perl-based ruleset language

BEC / impersonation defense

Targeted Attack Protection (TAP) and Email Fraud Defense

impostor email detection analyzing message headers, sender IP, language; visibility into phishing URLs and attachments

Core platform focus

vendor email compromise (VEC), executive impersonation, internal account compromise, lateral phishing all detected by behavioral baselining rather than reputation/signature alone

Impersonation Protect module analyzes header anomalies, sender patterns, and…

content for executive impersonation and BEC attempts

Basic header and content-based rules

no behavioral AI baseline like modern API-based platforms — organizations needing strong BEC detection typically pair with additional tooling or accept the rule-based detection level

URL & attachment defense

URL Defense rewrites and sandboxes URLs at click-time

Attachment Defense sandboxes attachments; integrates with Proofpoint Threat Response for automated remediation

URL and attachment analysis as part of behavioral detection

less emphasis on time-of-click URL rewriting (different architectural choice than traditional SEGs)

URL Protect rewrites links for time-of-click sandboxing

Attachment Protect scans attachments via static and dynamic analysis; integrates with Mimecast Threat Intelligence

URL blacklists, attachment filtering by file type/extension/MIME type,…

multi-engine attachment scanning via integrated AV engines

DMARC / authentication

Email Fraud Defense (separately licensed) is Proofpoint's DMARC enforcement and…

visibility product; supports SPF, DKIM, DMARC; reports on domain abuse

DMARC monitoring and visibility supported

not a dedicated DMARC enforcement vendor like specialized products in that space

Mimecast DMARC Analyzer (separately licensed) provides DMARC implementation and…

ongoing management; supports SPF, DKIM, DMARC reporting

DMARC/SPF/DKIM evaluation typically delegated to MTA (Postfix/Exim/Sendmail)…

which check authentication before MailScanner content scanning; OpenDMARC and OpenDKIM commonly paired

Email archiving / continuity

Proofpoint Enterprise Archive (separately licensed) provides cloud archiving…

and e-discovery; email continuity service available as add-on; supports legal hold and supervision

Not a core focus

Abnormal positions as an email security layer, not an archiving or continuity vendor; organizations typically pair with Microsoft 365 native archiving or a separate archiving product

Mimecast Cloud Archive is a core platform strength

tamper-proof email archiving with triplicate copies, legal hold, e-discovery, FINRA/SEC/FCA supervision; email continuity service included in base tiers

Not a core feature

typically paired with separate archiving solutions (Cyrus IMAP, Dovecot archiving, dedicated archive products) and mail server HA setups

Reporting & SOC integration

Threat Response Auto-Pull for SOC remediation of malicious emails post-delivery

PhishAlarm reporting button for users; SIEM forwarding via syslog and API; integration with Splunk, Sentinel, QRadar

AI Security Mailbox automates triage and remediation of user-reported phishing

SIEM forwarding via Splunk and Microsoft Sentinel; SOC workload reduction often cited as a key value driver; integrations with SOAR platforms

User reporting via Mimecast plugin

admin console for incident review; SIEM forwarding via syslog and API; SOAR integration; integration with SOC tooling (Splunk, Sentinel, QRadar)

MailWatch and Baruwa provide web UIs for quarantine review and reporting

syslog forwarding for SIEM ingestion; quarantine management via web interface

✓ Compliance & certifications

1 dimension

Compliance certifications

SOC 2 Type II, ISO 27001, ISO 27018, HIPAA-aligned, GDPR, FedRAMP Moderate…

(Government tier); supports compliance reporting for HIPAA, PCI DSS, FINRA, SOX

SOC 2 Type II, ISO 27001, GDPR

HIPAA-aligned configurations available

SOC 2 Type II, ISO 27001, HIPAA-aligned, GDPR

supports compliance for FINRA, SEC, FCA, SOX (especially via Mimecast Cloud Archive and Supervision modules)

Software has no specific certifications

users deploy in their own compliant environments. Organizations operating MailScanner-based gateways are responsible for their own compliance posture.

◧ Positioning

3 dimensions

Target deployment

Mid-market to enterprise wanting mature SEG with broad threat protection, DLP,…

and compliance portfolio

Organizations wanting modern API-based email security focused on BEC, vendor…

email compromise, and account takeover detection

Mid-market to enterprise wanting integrated email security + archiving +…

continuity + human risk management

Organizations running self-hosted mail servers, ISPs, MSPs, technical teams…

wanting full control of mail filtering without per-user licensing

Strengths cited

Long-established email security vendor with broad portfolio (TAP, DLP,…

encryption, archiving, security awareness training), strong threat intelligence (Emerging Threats Pro / ET Pro), modular product set covers most email security needs from one vendor

Behavioral AI builds employee and vendor relationship baselines

API integration deploys in minutes without mail flow disruption; strong BEC and vendor email compromise detection; complements existing Microsoft 365/Defender deployments; recognized Leader in Gartner Magic Quadrant for Email Security Platforms

Strong integrated platform combining email security, archiving, continuity, and…

human risk management; built-in email continuity is differentiating (included in base tiers vs add-on for many competitors); broad compliance and archiving capabilities; 42,000+ business customers

Free open source mail filter framework that bundles multiple scanning engines…

(SpamAssassin, ClamAV, F-Prot, etc.), highly customizable rule sets, widely deployed in self-hosted mail server environments, mature project with long operational track record, no per-user licensing

Where it fits less well

Modular licensing means each capability (TAP, archiving, DLP, awareness…

training) may be priced separately; setup involves MX record changes and mail flow redirection; initial configuration depth often benefits from professional services or experienced reseller

Designed as primary platform OR layered with existing email security

strategy choice matters for buyers; API approach requires granting access to email content; advanced modules (VIP protection, supply chain fraud, advanced threat intelligence) may carry incremental fees

Quote-based pricing varies 30-100% between similar organizations based on tier,…

modules, and term; renewal pricing increases are commonly reported and worth negotiating multi-year terms to mitigate; module additions stack as percentage increases above base tier

Requires Linux mail server administration expertise

setup and tuning depth means production deployments take meaningful operational investment; primarily a fit for self-hosted mail environments rather than Microsoft 365 / Google Workspace tenants (which use API-based or SEG products instead)

Head-to-head comparisons

3 pairs

◧ Bottom line

Last updated 6 July 2026

How this category breaks down This page compares 4 Email Security / SEG tools. Open-source / free-tier options: MailScanner. Commercial platforms: Proofpoint, Abnormal Security, Mimecast. Use the comparison table above to match each tool’s stated best-fit to your environment.

Frequently asked questions

3 questions

Which Email Security / SEG tools does this comparison cover?

This comparison covers 4 Email Security / SEG tools: Proofpoint, Abnormal Security, Mimecast, MailScanner.

Which Email Security / SEG tools are open-source or offer a free tier?

Open-source or free-tier options: MailScanner.

Which Email Security / SEG tools are commercial (paid)?

Commercial / paid options: Proofpoint, Abnormal Security, Mimecast.

Methodology Comparison data synthesized from publicly available vendor documentation, MITRE Engenuity ATT&CK Evaluations, AV-TEST results, Gartner Peer Insights, G2/Capterra/TrustRadius reviews, anonymized transaction data (Vendr, CostBench, CheckThat.ai), and publicly reported pricing as of May 2026. defend.network is independent and has no commercial relationship with the vendors compared.