November 5, 2026 - 6 min read

By PhishClean Research Team

Best anti-phishing tools for small business and MSSPs in 2026

Start with what you already pay for, then add a layer that covers the gap. Here is how the common options compare, from what each vendor documents publicly.

A recurring question on r/cybersecurity asks for the best anti-phishing tool on the market for small to medium business, specifically for an MSSP. The top answer in one thread: look at IRONSCALES or Abnormal Security for the behavioral and AI detection layer, since both handle multi-tenant setups. That's a reasonable starting point, but it skips the question that saves the most money: what do your clients already own?

At a glance

Start here: Microsoft Defender for Office 365

If the client is on Microsoft 365, begin with what's included. Microsoft says Plan 1 comes with Microsoft 365 Business Premium and E3, and it's a $2 add-on for many other plans. That gets you Safe Links, Safe Attachments, and impersonation protection. Plan 2 adds attack simulation training, Threat Explorer and automated investigation.

Many tenants never get the full value because impersonation protection isn't configured by default. The default policy doesn't protect your CEO's name until someone adds it. Our settings guide walks through it.

For MSPs, Microsoft 365 Lighthouse offers a default SMB security baseline and multi-tenant views, at no extra cost to partners in the Cloud Solution Provider program.

Choose it if your clients are all-Microsoft and budgets are tight. Keep in mind that it only covers Microsoft 365 and that tuning takes real work.

IRONSCALES

The most MSP-oriented of these three on paper. Its partner page describes a multi-tenant, API-based platform that bundles detection and remediation with security awareness training, phishing simulation, DMARC management and outbound encryption, in one console. If you're currently stitching those together from separate vendors, the bundling is the main draw. Its pricing page lists an MSP-oriented Email Protect Pro tier, but every plan leads to a quote.

Choose it if you want one tool and one console for email security and awareness across many small clients.

Abnormal AI

Formerly Abnormal Security. It focuses on behavioral detection of things like invoice fraud and impersonation, and it describes itself as augmenting Microsoft's native security rather than replacing it. It connects by API to Microsoft 365 and Google Workspace, with no MX or DNS changes. Its Multi-Tenant Management feature is built for adding tenants quickly and reporting across them, and it runs an MSSP partner track.

Choose it if business email compromise is the risk you most need to reduce. Ask about minimum seat counts for your smallest clients. We couldn't find a public answer.

Check Point Harmony Email & Collaboration

Formerly Avanan. It's API-based rather than a mail gateway, and typically starts in monitor-only mode before moving to inline protection, which makes for a low-risk trial. MSPs manage it through the Infinity Portal, with configuration templates that can be pushed to multiple tenants. It's a natural choice if you already sell other Check Point products.

Choose it if you want coverage across email and collaboration apps from a vendor you already use.

Where a browser layer fits

Email tools only see email. Phishing also arrives through Teams, Slack, LinkedIn, search ads, text messages and personal webmail opened on a work laptop. All of it ends up in the browser. PhishClean checks the page itself on the device, which covers those paths and adds warnings for threats such as fake CAPTCHA pages, disguised downloads and card skimmers.

It's not a substitute for email security. It doesn't remove a message from an inbox, it gives you no central view of threats across clients, and we don't have an MSSP program yet. It suits a small business that wants an extra layer for a few dollars per user, and privacy-sensitive clients, since no browsing data comes to us. Other browser-level options are in our roundup and business alternatives guide.

How to pick for a real client

1. Turn on what's already paid for. Apply Microsoft's preset security policies and configure impersonation protection. Set up DMARC.
2. Fix identity next. Phishing-resistant MFA for admins and finance reduces the cost of any miss, whichever filter you buy.
3. Trial an API tool in monitor mode. Connect it to one real tenant for a couple of weeks and count what your current setup missed. This is the only comparison that matters, and API tools make it easy because no mail routing changes.
4. Count false positives too. A tool that quarantines invoices creates work for you and pain for your clients. Ask how each handles user reports, and how quickly it learns from them.
5. Add a browser layer last if clients still get caught outside email.

Questions to put to any vendor

• What's the smallest tenant and the minimum commitment?
• Can I see all tenants, alerts and reports in one console, and apply one policy to all of them?
• Who handles reported messages: my team, your SOC or an automated process?
• Which data leaves the tenant, where is it stored, and for how long?
• Does the tool scan links at click time, and does it remove delivered mail automatically?
• What happens to my clients' protection and data if we stop paying?

Frequently asked questions

What is the best anti-phishing tool for a small business?

If you use Microsoft 365, start with Defender for Office 365, which is included in Business Premium and costs $2 per user per month as Plan 1. Configure it properly, set up DMARC and phishing-resistant MFA, then trial an API tool in monitor mode to see what's still getting through.

Which anti-phishing tools work well for MSSPs?

IRONSCALES, Abnormal AI and Check Point Harmony Email & Collaboration all document multi-tenant management for service providers, and Microsoft 365 Lighthouse covers Defender-based stacks. Trial them on a real tenant, since published detection comparisons are limited.

Do I need a separate tool if I already have Microsoft Defender?

Not necessarily. Many tenants haven't fully configured what they own. Fix that first, then measure what gets through. An API-based tool may be worth it if impersonation and invoice fraud are still reaching people.

Is a browser extension enough to protect a business from phishing?

No. It's a useful extra layer because it covers links from any source, but it doesn't filter email or give you a central view of threats. Use it alongside email security and strong sign-in methods.

Sources

• Microsoft: Defender for Office 365 plans and pricing
• Microsoft Learn: Why do I need Defender for Office 365?
• Microsoft Learn: Microsoft 365 Lighthouse overview
• IRONSCALES: Partner program
• IRONSCALES: Pricing
• Abnormal AI: Partner programs
• Abnormal AI: Multi-tenant management
• Abnormal AI + Microsoft
• Abnormal AI: Data sheet (API deployment with no MX or DNS changes)
• Check Point: MSP configuration templates
• Check Point CheckMates: Harmony Email & Collaboration overview
• Check Point and Pax8 partnership

Last updated: 5 November 2026