License & Deployment Mix: 20 tools – 6 OSS, 11 SaaS. (OSS and SaaS counts can overlap when an open-source tool also offers a vendor-hosted edition.)
Overview
Email security encompasses the tools and techniques that protect email infrastructure from spam, phishing, malware, business email compromise (BEC), and data exfiltration. An email security gateway (SEG) sits in front of the mail server and filters inbound and outbound messages before they reach users or leave the organisation.
Email security platforms provide:
- Anti-spam filtering – content analysis, Bayesian classification, DNS blocklists (DNSBL), greylisting, and sender reputation scoring to block unsolicited email
- Anti-phishing – URL rewriting and sandboxing, display-name spoofing detection, lookalike domain detection, and brand impersonation protection
- Anti-malware – attachment scanning with multiple AV engines, sandboxing (detonation), and content disarm and reconstruction (CDR) to neutralise weaponised documents
- SPF / DKIM / DMARC – sender authentication protocols that verify the sending domain’s identity and prevent spoofing; DMARC reporting and enforcement
- BEC protection – detecting business email compromise attempts (CEO fraud, invoice redirection, payroll diversion) using AI/ML analysis of email patterns, writing style, and sender behaviour
- Encryption – TLS enforcement for transport, S/MIME and PGP for message-level encryption, and policy-based encryption gateways
- DLP for email – scanning outbound email for sensitive data (credit card numbers, SSNs, PII, intellectual property) and blocking or encrypting before delivery
- Quarantine management – admin and user self-service quarantine review; digest notifications; allow/deny lists per user
- Archive and compliance – some SEGs include archiving (see Email Archiving for dedicated archiving tools)
The information on these pages was researched by a combination of human review and large language models. To suggest an addition or correction, please contact us. Prepared by Rhodium Systems Inc., author of the ResorsIT platform — a unified IT operations management platform for IT teams and MSPs that integrates a curated suite of open-source, commercial, and SaaS applications into a single system with shared identity, single sign-on, access control, and a common audit trail. Use this catalogue only as a starting point for your own research, and review any tool carefully against your own requirements before relying on it. Catalogue data version 2026.197.
Comparison
Deployment Model
| Tool | Self-Hosted | SaaS | License |
|---|---|---|---|
| rspamd | Yes | No | Apache 2.0 |
| SpamAssassin | Yes | No | Apache 2.0 |
| Proxmox Mail Gateway | Yes | No | AGPL-3.0 |
| MailScanner | Yes | No | GPL-2.0 |
| Scrollout F1 | Yes | No | GPL-3.0 |
| ClamAV | Yes | No | GPL-2.0 |
| Mimecast | No | Yes | Proprietary |
| Proofpoint | No | Yes | Proprietary |
| Barracuda | Yes | Yes | Proprietary |
| Hornetsecurity | No | Yes | Proprietary |
| FortiMail | Yes | Yes | Proprietary |
| Cisco Secure Email | Yes | Yes | Proprietary |
| Trend Micro | No | Yes | Proprietary |
| IRONSCALES | No | Yes | Proprietary |
| Abnormal Security | No | Yes | Proprietary |
| Avanan | No | Yes | Proprietary |
Detection Capabilities
| Tool | Anti-Spam | Anti-Phishing | Anti-Malware | BEC | Sandbox |
|---|---|---|---|---|---|
| rspamd | Yes | Yes | Yes (ClamAV) | No | No |
| SpamAssassin | Yes | Limited | No* | No | No |
| Proxmox Mail GW | Yes | Yes | Yes (ClamAV) | No | No |
| Mimecast | Yes | Yes | Yes | Yes | Yes |
| Proofpoint | Yes | Yes | Yes | Yes | Yes |
| Barracuda | Yes | Yes | Yes | Yes | Yes |
| Hornetsecurity | Yes | Yes | Yes | Yes | Yes |
| FortiMail | Yes | Yes | Yes | Yes | Yes |
| Cisco Secure Email | Yes | Yes | Yes | Yes | Yes |
| IRONSCALES | Yes | Yes | Yes | Yes | No |
| Abnormal Security | No | Yes | No | Yes | No |
| Avanan | Yes | Yes | Yes | Yes | Yes |
* = requires external ClamAV integration
Protocol Support
| Tool | SPF | DKIM | DMARC | ARC | BIMI |
|---|---|---|---|---|---|
| rspamd | Yes | Yes (sign+verify) | Yes | Yes | No |
| SpamAssassin | Yes | Yes (verify) | Yes | No | No |
| Proxmox Mail GW | Yes | Yes | Yes | No | No |
| Mimecast | Yes | Yes | Yes | Yes | Yes |
| Proofpoint | Yes | Yes | Yes | Yes | Yes |
| Barracuda | Yes | Yes | Yes | No | No |
| Hornetsecurity | Yes | Yes | Yes | Yes | Yes |
SSO / Authentik Integration
| Tool | OIDC | SAML | SCIM | Authentik Notes |
|---|---|---|---|---|
| rspamd | No | No | No | Web UI; forward-auth via Traefik |
| Proxmox Mail GW | No | No | No | Web UI; forward-auth via Traefik |
| Mimecast | No | Yes | Yes | SAML SSO + SCIM provisioning |
| Proofpoint | No | Yes | Yes | SAML SSO + SCIM provisioning |
| Barracuda | No | Yes | No | SAML SSO for cloud console |
| Hornetsecurity | Yes | Yes | Yes | OIDC/SAML + SCIM |
| Cisco Secure Email | No | Yes | No | SAML SSO for cloud console |
| IRONSCALES | No | Yes | Yes | SAML SSO + SCIM |
| Abnormal Security | No | Yes | Yes | SAML SSO + SCIM |
| Avanan | No | Yes | No | SAML SSO via Check Point |
DMARC Management Tools
| Tool | Reporting | Enforcement | SPF Mgmt | BIMI |
|---|---|---|---|---|
| dmarcian | Yes | Yes | Yes | Yes |
| Valimail | Yes | Yes (automated) | Yes | Yes |
| EasyDMARC | Yes | Yes | Yes | Yes |
| PowerDMARC | Yes | Yes | Yes | Yes |
Tools
20 tools.
Abnormal Security
Abnormal Security is a cloud-native email security platform that uses behavioral AI to detect and prevent business email compromise (BEC), credential phishing, account takeover, and other socially engineered attacks that evade traditional s…
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Avanan / Check Point Harmony Email
Avanan, acquired by Check Point Software in 2021 and rebranded as Check Point Harmony Email & Collaboration, is an inline API-based email security platform that scans messages before they reach the user’s inbox – without requiring MX recor…
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Barracuda Email Security Gateway
Barracuda Email Security Gateway (ESG) is a widely deployed commercial email security appliance from Barracuda Networks, available as hardware, virtual, and cloud-hosted options.
License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none
Cisco Secure Email
Cisco Secure Email (formerly Cisco Email Security Appliance / IronPort) is an enterprise-grade secure email gateway powered by Cisco Talos, one of the world’s largest commercial threat intelligence organizations.
License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none
ClamAV
ClamAV is the de facto standard open-source antivirus engine, maintained by Cisco Talos since Cisco acquired Sourcefire in 2013.
License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none
dmarcian
dmarcian is the original DMARC deployment and management platform, founded by Tim Draegen, one of the co-authors of the DMARC specification.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
EasyDMARC
EasyDMARC is a cloud-based email authentication platform that provides DMARC monitoring, SPF management, DKIM validation, and BIMI support.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Fortinet FortiMail
Fortinet FortiMail is a secure email gateway that provides comprehensive inbound and outbound email protection as part of the Fortinet Security Fabric.
License: Proprietary (proprietary) · Kind: web · Deploy: appliance · SSO: none
Hornetsecurity
Hornetsecurity is a European cloud email security provider offering comprehensive email protection, compliance, and backup services with a strong focus on Microsoft 365 environments.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
IRONSCALES
IRONSCALES is a cloud-native email security platform that operates as an Integrated Cloud Email Security (ICES) solution, complementing or replacing traditional secure email gateways.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
MailScanner
MailScanner is an open-source email security suite that wraps SpamAssassin and ClamAV (plus optional commercial AV engines) into a unified content scanning framework for Postfix, Sendmail, Exim, and ZMailer MTAs.
License: GPL-2.0-only (OSS) · Kind: web · Deploy: native · SSO: none
Mimecast
Mimecast is a leading cloud-based email security platform that provides integrated secure email gateway (SEG), email archiving, continuity, awareness training, and brand protection services.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
PowerDMARC
PowerDMARC is a cloud-based email authentication platform that provides DMARC deployment, monitoring, enforcement, and reporting alongside comprehensive SPF, DKIM, BIMI, MTA-STS, and TLS-RPT management.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Proofpoint Email Protection
Proofpoint Email Protection is the market-leading enterprise email security platform, consistently ranked as the top secure email gateway by Gartner and Forrester.
License: Proprietary (proprietary) · Kind: web · Deploy: native, saas · SSO: none
Proxmox Mail Gateway
Proxmox Mail Gateway (PMG) is a full-featured open-source email security gateway that sits between the internet and the internal mail server, filtering all incoming and outgoing email.
License: AGPL-3.0-only (OSS) · Kind: web · Deploy: appliance · SSO: none
rspamd
rspamd is a high-performance, event-driven spam filtering system designed for modern mail infrastructure.
License: Apache-2.0 (OSS) · Kind: web · Deploy: native, docker · SSO: none
Scrollout F1
Scrollout F1 is an open-source email firewall gateway designed to provide enterprise-grade email security with minimal configuration.
License: GPL-3.0-only (OSS) · Kind: web · Deploy: native, appliance · SSO: none
SpamAssassin
Apache SpamAssassin is the most widely deployed open-source spam filtering platform, maintained by the Apache Software Foundation since 2004.
License: Apache-2.0 (OSS) · Kind: web · Deploy: native · SSO: none
Trend Micro Email Security
Trend Micro Email Security is a cloud-native email protection service that provides pre-delivery and post-delivery defense against spam, phishing, BEC, ransomware, and advanced targeted attacks.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: none
Valimail
Valimail is an automated email authentication platform that specializes in achieving DMARC enforcement at scale.
License: Proprietary (proprietary) · Kind: web · Deploy: saas · SSO: OIDC
