# Microsoft Defender for Office 365 alternatives and competitors (2026) The closest Microsoft Defender for Office 365 alternatives are [Fortra Email Security & Anti-Phishing](https://cybersectools.com/tools/fortra-email-security-and-anti-phishing), [Cisco Secure Email Threat Defense](https://cybersectools.com/tools/cisco-secure-email-threat-defense) and [KnowBe4 Cloud Email Security](https://cybersectools.com/tools/knowbe4-cloud-email-security). Picking a Microsoft Defender for Office 365 alternative comes down to fit: Email Security Platforms coverage, your environment, your integrations and your budget. So each option below shows what it covers, how it deploys, its pricing model and the company behind it. 42 alternatives. Closest matches: Fortra Email Security & Anti-Phishing, Cisco Secure Email Threat Defense, KnowBe4 Cloud Email Security. ## The product [Microsoft Defender for Office 365](https://cybersectools.com/tools/microsoft-defender-for-office-365) by Microsoft Email and collaboration security for Microsoft 365 environments Category: [Email & Messaging Security](https://cybersectools.com/categories/email-security) · Pricing model: Commercial Need the answer fast? [Best Email Security Solutions for Business](https://cybersectools.com/shortlists/best-email-security-platforms) picks Proofpoint Core Email Protection, Microsoft Defender for Office 365, Mimecast Advanced Email Security and 4 more. ## Microsoft Defender for Office 365 alternatives and competitors Microsoft Defender for Office 365 is a commercial [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) solution made by Microsoft. The closest matches by shared tags and NIST CSF 2.0 coverage are [Fortra Email Security & Anti-Phishing](https://cybersectools.com/tools/fortra-email-security-and-anti-phishing), [Cisco Secure Email Threat Defense](https://cybersectools.com/tools/cisco-secure-email-threat-defense), [KnowBe4 Cloud Email Security](https://cybersectools.com/tools/knowbe4-cloud-email-security), [ConnectWise Email Security](https://cybersectools.com/tools/connectwise-email-security), and [ID Agent Graphus](https://cybersectools.com/tools/id-agent-graphus). All 42 alternatives on this page are ranked the same way. ## The closest Microsoft Defender for Office 365 alternatives These 8 solutions overlap most with Microsoft Defender for Office 365. Each one says what the product does and, when the overlap is big enough, which capabilities it shares. ### 1. [Fortra Email Security & Anti-Phishing](https://cybersectools.com/tools/fortra-email-security-and-anti-phishing) (Featured) Email security platform protecting against phishing, BEC, and data loss [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: DMARC email authentication and enforcement, Business email compromise detection, Spear phishing protection, Account takeover detection, Data loss prevention for sensitive data [Fortra Email Security & Anti-Phishing alternatives](https://cybersectools.com/alternatives/fortra-email-security-and-anti-phishing) · [Microsoft Defender for Office 365 vs Fortra Email Security & Anti-Phishing](https://cybersectools.com/compare/fortra-email-security-and-anti-phishing-vs-microsoft-defender-for-office-365) ### 2. [Cisco Secure Email Threat Defense](https://cybersectools.com/tools/cisco-secure-email-threat-defense) Email threat protection for Microsoft 365 with advanced detection capabilities [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 9 listed. See them on the [Cisco Secure Email Threat Defense page](https://cybersectools.com/tools/cisco-secure-email-threat-defense#features). [Cisco Secure Email Threat Defense alternatives](https://cybersectools.com/alternatives/cisco-secure-email-threat-defense) · [Microsoft Defender for Office 365 vs Cisco Secure Email Threat Defense](https://cybersectools.com/compare/cisco-secure-email-threat-defense-vs-microsoft-defender-for-office-365) ### 3. [KnowBe4 Cloud Email Security](https://cybersectools.com/tools/knowbe4-cloud-email-security) AI-driven email security platform for Microsoft 365 inbound/outbound threats [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 10 listed. See them on the [KnowBe4 Cloud Email Security page](https://cybersectools.com/tools/knowbe4-cloud-email-security#features). [KnowBe4 Cloud Email Security alternatives](https://cybersectools.com/alternatives/knowbe4-cloud-email-security) · [Microsoft Defender for Office 365 vs KnowBe4 Cloud Email Security](https://cybersectools.com/compare/knowbe4-cloud-email-security-vs-microsoft-defender-for-office-365) ### 4. [ConnectWise Email Security](https://cybersectools.com/tools/connectwise-email-security) Email security platform with AI threat detection, BEC protection, and DLP [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 10 listed. See them on the [ConnectWise Email Security page](https://cybersectools.com/tools/connectwise-email-security#features). [ConnectWise Email Security alternatives](https://cybersectools.com/alternatives/connectwise-email-security) · [Microsoft Defender for Office 365 vs ConnectWise Email Security](https://cybersectools.com/compare/connectwise-email-security-vs-microsoft-defender-for-office-365) ### 5. [ID Agent Graphus](https://cybersectools.com/tools/id-agent-graphus) AI-powered anti-phishing platform for Microsoft 365 & Google Workspace. [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 10 listed. See them on the [ID Agent Graphus page](https://cybersectools.com/tools/id-agent-graphus#features). [ID Agent Graphus alternatives](https://cybersectools.com/alternatives/id-agent-graphus) · [Microsoft Defender for Office 365 vs ID Agent Graphus](https://cybersectools.com/compare/id-agent-graphus-vs-microsoft-defender-for-office-365) ### 6. [Fortinet FortiMail Email and Workspace Security](https://cybersectools.com/tools/fortinet-fortimail-email-security) AI-powered email security platform protecting against phishing, BEC, and ATO [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 10 listed. See them on the [Fortinet FortiMail Email and Workspace Security page](https://cybersectools.com/tools/fortinet-fortimail-email-security#features). [Fortinet FortiMail Email and Workspace Security alternatives](https://cybersectools.com/alternatives/fortinet-fortimail-email-security) · [Microsoft Defender for Office 365 vs Fortinet FortiMail Email and Workspace Security](https://cybersectools.com/compare/fortinet-fortimail-email-security-vs-microsoft-defender-for-office-365) ### 7. [Cellopoint Cloud Email Security Solution](https://cybersectools.com/tools/cellopoint-cloud-email-security-solution) Cloud-based email security platform protecting against phishing, ransomware, BEC [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 8 listed. See them on the [Cellopoint Cloud Email Security Solution page](https://cybersectools.com/tools/cellopoint-cloud-email-security-solution#features). [Cellopoint Cloud Email Security Solution alternatives](https://cybersectools.com/alternatives/cellopoint-cloud-email-security-solution) · [Microsoft Defender for Office 365 vs Cellopoint Cloud Email Security Solution](https://cybersectools.com/compare/cellopoint-cloud-email-security-solution-vs-microsoft-defender-for-office-365) ### 8. [Mimecast Advanced Email Security](https://cybersectools.com/tools/mimecast-advanced-email-security) Email security platform protecting M365 & Google Workspace from threats [Email Security Platforms](https://cybersectools.com/categories/email-security-platforms) · Commercial Key features: 10 listed. See them on the [Mimecast Advanced Email Security page](https://cybersectools.com/tools/mimecast-advanced-email-security#features). [Mimecast Advanced Email Security alternatives](https://cybersectools.com/alternatives/mimecast-advanced-email-security) · [Microsoft Defender for Office 365 vs Mimecast Advanced Email Security](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-mimecast-advanced-email-security) ## All 42 products like Microsoft Defender for Office 365 The 8 above, plus: - [Abnormal AI Security Mailbox](https://cybersectools.com/tools/abnormal-security-ai-security-mailbox): AI-powered email security operations platform for automated threat triage (Commercial) - [ESET Cloud Office Security](https://cybersectools.com/tools/eset-cloud-office-security): Cloud email security for Microsoft 365 and Google Workspace applications (Commercial) - [Bitdefender GravityZone Extended Email Security](https://cybersectools.com/tools/bitdefender-gravityzone-extended-email-security): Cloud-native email security platform with SEG and API-based protection (Commercial) - [Broadcom Symantec Email Security](https://cybersectools.com/tools/broadcom-symantec-email-security): Enterprise email security platform for cloud and on-premise deployments (Commercial) - [OPSWAT MetaDefender Email Security](https://cybersectools.com/tools/opswat-metadefender-email-security): Email security platform protecting against phishing, malware, and exploits (Commercial) - [VIPRE Integrated Email Security (IES)](https://cybersectools.com/tools/vipre-integrated-email-security-ies): Email security platform for Microsoft 365 with AI-based threat detection (Commercial) - [Mesh 365](https://cybersectools.com/tools/mesh-365): API-based email security platform for Microsoft 365 environments (Commercial) - [Kaseya 365 Advanced Threat Protection](https://cybersectools.com/tools/kaseya-365-advanced-threat-protection): ATP solution for SaaS & email with AI-driven detection & auto-response (Commercial) - [Vircom Email Security](https://cybersectools.com/tools/vircom-email-security): Email security platform enhanced with multi-tenant mgmt & automation tools (Commercial) - [GLIMPS Email Security for M365](https://cybersectools.com/tools/glimps-email-security-for-m365): AI-based email security for M365 with phishing, BEC & malware detection. (Commercial) - [Upfort](https://cybersectools.com/tools/upfort): Unified AI-powered cybersecurity & cyber insurance platform for SMBs. (Commercial) - [Ocean Agentic Email Security Platform](https://cybersectools.com/tools/ocean-agentic-email-security-platform): Agentic AI email security platform that investigates emails pre-delivery. (Commercial) - [Hornetsecurity](https://cybersectools.com/tools/hornetsecurity): Cloud security platform for M365 covering email, backup, and awareness. (Commercial) - [INKY Behavioral Email Security Platform](https://cybersectools.com/tools/inky-behavioral-email-security-platform): Behavioral email security platform protecting inbound, outbound, and internal mail (Commercial) - [Sophos Email](https://cybersectools.com/tools/sophos-email): Email security platform with phishing/BEC protection and MDR/XDR integration (Commercial) - [TrustLayer Mail](https://cybersectools.com/tools/trustlayer-mail): Email security platform with inline threat protection and compliant archiving (Commercial) - [GreatHorn Email Security](https://cybersectools.com/tools/greathorn-email-security): Cloud-native email security platform for phishing detection and response (Commercial) - [Trustifi AI Powered Email Security](https://cybersectools.com/tools/trustifi-ai-powered-email-security): AI-powered email security platform for threat detection and compliance (Commercial) - [Proofpoint Core Email Protection](https://cybersectools.com/tools/proofpoint-threat-protection): Email security platform with AI-based threat detection and DLP capabilities (Commercial) - [Darktrace Email Security](https://cybersectools.com/tools/darktrace-email-security): AI-powered email security platform detecting threats across email and messaging (Commercial) - [TitanHQ Cybersecurity Bundles](https://cybersectools.com/tools/titanhq-cybersecurity-bundles): Bundled cybersecurity solutions for MSPs and end users with email protection (Commercial) - [IRONSCALES Adaptive AI Email Security](https://cybersectools.com/tools/ironscales-adaptive-ai-email-security): AI-powered email security platform with behavioral detection and automation (Commercial) - [Infonaligy Proofpoint Email Security](https://cybersectools.com/tools/infonaligy-proofpoint-email-security): Managed Proofpoint email security service for phishing & BEC protection. (Commercial) - [TitanHQ Security Bundles](https://cybersectools.com/tools/titanhq-security-bundles): Tiered cybersecurity bundles combining email, DNS, backup & SAT. (Commercial) - [NoSpamProxy Protection](https://cybersectools.com/tools/nospamproxy-protection): Email gateway that blocks spam, phishing and malware before inbox delivery, made (Commercial) - [Cloudflare Cloud Email Security](https://cybersectools.com/tools/cloudflare-cloud-email-security): 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. (Commercial) - [SorbSecurity Cloud Email Security](https://cybersectools.com/tools/sorbsecurity-cloud-email-security): Cloud-based email security platform protecting against phishing & ransomware (Commercial) - [Zivver Secure Business Email](https://cybersectools.com/tools/zivver-secure-business-email): All-in-one email security platform for threat protection and compliance (Commercial) - [MX Layer Email Security](https://cybersectools.com/tools/mx-layer-email-security): Cloud-based email security platform with AI-powered threat detection (Commercial) - [xorlab Email Security](https://cybersectools.com/tools/xorlab-email-security): AI-driven email security platform for detecting advanced email threats (Commercial) - [Trend Micro Trend Vision One™](https://cybersectools.com/tools/trend-micro-trend-vision-onetm): AI-powered email and collaboration security platform for threat detection (Commercial) - [AnubisNetworks Email Security](https://cybersectools.com/tools/anubisnetworks-email-security): Email security platform protecting against fraud, malware, and spam threats (Commercial) - [Material Security Email Security](https://cybersectools.com/tools/material-security-email-security): Cloud workspace security platform for email, files, and account protection (Commercial) - [AI-Powered Email Security & DMARC Protection](https://cybersectools.com/tools/emailinspect): AI-powered DMARC monitoring and email authentication security platform (Commercial) ## Alternatives to each of these [Fortra Email Security & Anti-Phishing alternatives](https://cybersectools.com/alternatives/fortra-email-security-and-anti-phishing) · [Cisco Secure Email Threat Defense alternatives](https://cybersectools.com/alternatives/cisco-secure-email-threat-defense) · [KnowBe4 Cloud Email Security alternatives](https://cybersectools.com/alternatives/knowbe4-cloud-email-security) · [ConnectWise Email Security alternatives](https://cybersectools.com/alternatives/connectwise-email-security) · [ID Agent Graphus alternatives](https://cybersectools.com/alternatives/id-agent-graphus) · [Fortinet FortiMail Email and Workspace Security alternatives](https://cybersectools.com/alternatives/fortinet-fortimail-email-security) · [Cellopoint Cloud Email Security Solution alternatives](https://cybersectools.com/alternatives/cellopoint-cloud-email-security-solution) · [Mimecast Advanced Email Security alternatives](https://cybersectools.com/alternatives/mimecast-advanced-email-security) · [Abnormal AI Security Mailbox alternatives](https://cybersectools.com/alternatives/abnormal-security-ai-security-mailbox) · [ESET Cloud Office Security alternatives](https://cybersectools.com/alternatives/eset-cloud-office-security) · [Bitdefender GravityZone Extended Email Security alternatives](https://cybersectools.com/alternatives/bitdefender-gravityzone-extended-email-security) · [Broadcom Symantec Email Security alternatives](https://cybersectools.com/alternatives/broadcom-symantec-email-security) ## Other Microsoft products [Azure DDoS Protection and Mitigation Services alternatives](https://cybersectools.com/alternatives/azure-ddos-protection-and-mitigation-services) · [Azure Key Vault alternatives](https://cybersectools.com/alternatives/key-vault) · [Azure Security alternatives](https://cybersectools.com/alternatives/azure-security) · [GitHub Code Security alternatives](https://cybersectools.com/alternatives/github-code-security) · [Microsoft Defender alternatives](https://cybersectools.com/alternatives/microsoft-defender) · [Microsoft Defender EASM alternatives](https://cybersectools.com/alternatives/microsoft-defender-external-attack-surface-management) · [Microsoft Defender Experts for XDR alternatives](https://cybersectools.com/alternatives/microsoft-defender-experts-for-xdr) · [Microsoft Defender XDR alternatives](https://cybersectools.com/alternatives/microsoft-defender-xdr) ## Compare Microsoft Defender for Office 365 with - [Microsoft Defender for Office 365 vs Fortra Email Security & Anti-Phishing](https://cybersectools.com/compare/fortra-email-security-and-anti-phishing-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs Cisco Secure Email Threat Defense](https://cybersectools.com/compare/cisco-secure-email-threat-defense-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs KnowBe4 Cloud Email Security](https://cybersectools.com/compare/knowbe4-cloud-email-security-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs ConnectWise Email Security](https://cybersectools.com/compare/connectwise-email-security-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs ID Agent Graphus](https://cybersectools.com/compare/id-agent-graphus-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs Fortinet FortiMail Email and Workspace Security](https://cybersectools.com/compare/fortinet-fortimail-email-security-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs Cellopoint Cloud Email Security Solution](https://cybersectools.com/compare/cellopoint-cloud-email-security-solution-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs Mimecast Advanced Email Security](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-mimecast-advanced-email-security) ## Microsoft Defender for Office 365 Alternatives FAQ ### What are the closest alternatives to Microsoft Defender for Office 365? The closest matches to Microsoft Defender for Office 365 by shared tags and NIST CSF 2.0 coverage are Fortra Email Security & Anti-Phishing, Cisco Secure Email Threat Defense, KnowBe4 Cloud Email Security, ConnectWise Email Security, and ID Agent Graphus. All of them are Email Security Platforms products. ### How many alternatives to Microsoft Defender for Office 365 are available? This page shows 42 alternatives to Microsoft Defender for Office 365, all in the Email Security Platforms category. Each one is matched on shared tags and NIST CSF 2.0 areas, and the closest matches rank first. ### Is Microsoft Defender for Office 365 free or commercial? Microsoft Defender for Office 365 is a commercial Email Security Platforms product. It needs a paid license or subscription. Only commercial alternatives are listed here. Free and open source products are under /free. ### What type of solution is Microsoft Defender for Office 365? Microsoft Defender for Office 365 is a Email Security Platforms product in the Email & Messaging Security category. You can compare it with the 42 other Email Security Platforms products on this page. --- Source: https://cybersectools.com/alternatives/microsoft-defender-for-office-365 For AI agents: every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md, and any product or compare page has a Markdown copy too (add .md to its URL). More on Microsoft Defender for Office 365 and its alternatives: 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=alternatives-md