A convincing phishing email can look like an ordinary part of the working day. An updated supplier invoice, a shared document or a calendar invitation from someone the employee knows. Business email compromise (BEC) may not include a malicious attachment at all because the request itself is the attack.
Email security software helps detect and remove these threats, but the tools vary in how they do it. The best choice depends on your mail environment and on whether one platform also needs to stretch across employee training, the devices people work on, and the AI tools they’re connecting. Those wider responsibilities start to matter the moment an email is followed up by a text or a phone call, or by a request to install something.
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Which email security tools should you shortlist?
If you want to consolidate email and workforce security
- Noon Security: brings inbox protection, device controls and employee learning into one platform that also governs AI use.
- KnowBe4: fits when the priority is pairing Defend’s inbound protection with its Security Awareness Training.
If you want to reduce routine email response work
- Noon Security: offers optional automated email remediation alongside its broader workforce protection.
- IRONSCALES gives teams focused on email operations configurable autonomous remediation.
If you need to address supplier fraud and executive impersonation
- Noon Security: covers phishing and business email compromise inside its workforce platform.
- Abnormal AI: builds its detection around identity and relationship context rather than message content alone.
- Proofpoint: pairs deep email investigation with enforcement you can tune.
If you need to keep investigations inside Microsoft
- Microsoft Defender for Office 365: suits teams already working in the Defender portal, with Plan 2 adding automated investigation and response.
If you want to shape detection to your own organization
- Sublime Security gives security engineers editable detections and backtesting to inspect how unusual business mail is handled.
Where email security tools often fall short
The request is the attack
Business email compromise often arrives with no attachment and no malicious link, just a believable ask to change bank details or approve a payment. A filter trained to catch bad files and URLs has nothing to catch, so the message sails through to someone who takes it at face value.
Detection is only half the job
A tool can flag a threat accurately and still make for a slow response. What matters day to day is how fast related messages surface, what gets handled without a human, and how a wrong verdict is reversed before a real invoice sits in quarantine overnight.
The inbox is only one channel
The email that gets through is often followed by a text or a call, or by the same employee installing a tool that shouldn’t touch company data. Email security tools often leave those follow-ups to whatever else the team has in place.
How we evaluated these tools: Each entry draws on the vendor’s own product and documentation pages, read at the time of writing, plus our own hands-on view where we have one. Where a capability depends on a license tier, enforcement mode or deployment model, we’ve said so.
Email security software compared
The configurations below identify the products being compared. Additional products from the same vendor may expand their coverage.
Top 10 email security platforms
1. Noon Security
What it does: Noon is Aikido Security’s workforce security platform, built to protect employees across the tools they use. Email protection catches phishing, business email compromise, credential harvesting and malware by weighing signals like sender identity, authentication, the links and attachments in a message and the action it’s actually asking for. It connects to Microsoft 365 and Google Workspace through their APIs, so there’s no mail rerouting to set up.
Why it stands out: The connection starts read-only. Noon watches before it touches anything, and an administrator grants permission before it moves a single message, then turns on automated remediation when the team is ready. It can move a message to trash or spam and pull it back to the inbox, while the uncertain verdicts are handled by your security team. That sits inside a platform that also handles what happens away from the inbox, through device protection and AI governance over the tools and MCP servers employees connect.
What to know: Device protection needs deployment beyond the mailbox connection, and any archiving, continuity or outbound controls you rely on should be scoped separately, since Noon’s focus is detection and response rather than mail flow.
2. Proofpoint Core Email Protection
What it does: Proofpoint Core Email Protection leans on behavioral analysis and threat intelligence to catch phishing, business email compromise and malicious content. It supports Microsoft 365 and Google Workspace, and you can deploy it through an API or as a secure email gateway.
Why it stands out: Proofpoint is worth considering for a mail setup that isn’t a single clean cloud tenant, where mail routes through existing gateways or spans on-premises and cloud mailboxes. Depending on how you configure it, inspection can happen inline, inside the mailbox, after delivery or at the moment someone clicks a link, which gives a large operation room to enforce the way it needs to. Its Threat Protection Workbench pulls related threats into a single investigation workflow.
What to know: Proofpoint’s portfolio runs wide, from training to data security to archiving, so the Core Email Protection name alone doesn’t tell you what’s in the bundle. Walk through the investigation and restoration tasks your administrators will own before you commit.
3. Mimecast Advanced Email Security
What it does: Mimecast Advanced Email Security covers phishing, impersonation and the malicious links and attachments that come with them. Its API and gateway options support cloud, on-premises and hybrid setups, which is much of its appeal.
Why it stands out: Mimecast makes sense when mail routing and the email services you already run shape the decision. Its investigation and automated remediation can sit alongside other Mimecast products, including archiving and security awareness training.
What to know: Match the deployment to the mailbox and continuity services you need, and review Mimecast’s plans at the package level. API access, archiving and the broader workforce features aren’t interchangeable inclusions, so confirm which ones your chosen tier carries before assuming the Advanced Email Security name covers them all.
4. Abnormal AI Inbound Email Security
What it does: Abnormal AI reads identity, relationships and message content together to flag a suspicious request, and it connects to Microsoft 365 and Google Workspace through APIs with automatic removal of malicious mail.
Why it stands out: The behavioral approach is what makes it strong against supplier fraud, executive impersonation and the messages that carry no obvious malicious file, which is exactly where content-only filters struggle. Analysts can open up the signals behind a verdict, search across mail, take action in bulk and work through quarantined messages, so a suspicious conversation can be investigated in its full context rather than one message at a time.
What to know: Test it against legitimate but unusual business conversations, not just attacks, since a relationship-aware model is where false positives tend to show. Keep the inbound purchase separate from Abnormal’s additional identity security, AI security and phishing-coaching products, because one email configuration doesn’t describe everything the vendor sells.
5. Microsoft Defender for Office 365
What it does: Microsoft Defender for Office 365 protects email and collaboration workloads inside the Microsoft environment, and its Plan 2 tier adds advanced investigation, response and attack simulation training.
Why it stands out: For an organization already living in the Defender portal, keeping email investigations there smooths how analysts move between related activity. Its automated investigation and response works through the relevant alerts and produces findings with remediation actions attached. Some of those need an administrator’s approval, while similarity clusters of malicious URLs and files can be cleaned up automatically, so routine threats don’t all wait on a human.
What to know: Verify the exact license entitlement and which policies are already switched on, because the brand covers a lot of ground and your tier may not include what you assume. Administrators still own the pending decisions. Assess endpoint protection and retention through their own products rather than reading them into the Defender name.
6. Check Point Email Security
What it does: Check Point Email Security analyzes identity, language and the links and attachments in a message to catch phishing, business email compromise and malware. It supports Microsoft 365, Google Workspace and the collaboration apps that sit around them.
Why it stands out: The useful distinction is its API deployment paired with inline prevention. An API connection doesn’t always mean a product waits for a threat to reach the inbox and then removes it, and here the enforcement mode is what decides whether the deployment simply monitors messages or actively blocks them before delivery. That gives a team the convenience of API onboarding without automatically giving up pre-delivery blocking.
What to know: Confirm the enforcement mode you’re selecting and the mail environment it supports. Check Point’s packages keep email protection distinct from additions such as archiving, AI phishing training and data loss prevention, so name those explicitly if they’re part of what you need rather than expecting them in the base.
7. IRONSCALES Email Protect
What it does: IRONSCALES Email Protect combines threat detection, link and attachment inspection and configurable autonomous remediation, connecting to Microsoft 365 and Google Workspace through APIs.
Why it stands out: The business Email Protect plan is the draw when a team wants to set exactly how much routine response runs on its own. Its investigation and reporting workflows handle the cases that still need an administrator, while the remediation settings let the organization pick its own operating point rather than accepting a vendor default. That adjustability is the real reason to look at it over a more fixed product.
What to know: Make sure you’re on the right business or managed-service package. Human Risk Management covers the training and simulations, while encryption and data loss prevention depend on the offering you select, so none of those are safe to assume. Define who reviews disputed verdicts and how legitimate mail gets restored before rollout.
8. Barracuda Email Protection
What it does: Barracuda Email Protection brings inbound protection and incident response together across several tiers of email service. The Premium Plus tier is the one compared here, and it adds cloud archiving, awareness training and phishing simulations.
Why it stands out: Barracuda is a practical pick when retention and employee education belong in the same buying decision as threat protection, rather than as separate purchases. It deploys through API, inline or MX-based configurations, so it fits different mail setups. The archive preserves records for search and retention while incident response deals with the malicious messages, two jobs that solve genuinely different problems under one roof.
What to know: Compare the named plan and the delivery model carefully, since a lower package won’t inherit Premium Plus features and managed-service training can be a paid add-on. Establish how the archive handles access, retention and export before you migrate any existing records into it.
9. KnowBe4 Defend
What it does: KnowBe4 Defend applies behavioral and linguistic analysis to inbound threats including phishing and business email compromise. It supports Microsoft 365 and Google Workspace and adds contextual coaching around a suspicious message.
Why it stands out: Defend makes most sense when you want email defense sitting next to KnowBe4 Security Awareness Training. That pairing brings live protection and an ongoing learning program into one vendor relationship, with Defend’s in-context warnings and the separate training curriculum playing complementary roles rather than overlapping. For a team already invested in KnowBe4, it’s the natural way to add inbound protection.
What to know: Deployment and remediation differ by mail platform. Microsoft supports inline and post-delivery options, while the documented Gmail workflow routes dangerous messages to Junk, so confirm what employees and administrators will actually see. Scope PhishER Plus or any outbound products separately where you need them.
10. Sublime Security
What it does: Sublime Security combines inbound protection with editable detections, threat hunting and automated response. It connects to Microsoft 365 and Google Workspace, and it runs as SaaS, private-cloud or fully self-hosted.
Why it stands out: Sublime suits security engineers who want to open up the detection logic and adapt it to their own organization rather than trust a closed box. Teams can hunt through historical messages, build fresh coverage from what they find and backtest a proposed change before it goes live. Its Autonomous Detection Engineer drafts and backtests organization-specific coverage for review, while response actions can quarantine, delete or warn depending on the call.
What to know: Decide who owns policy changes and approvals, because that control is the whole point and it needs a clear owner. Compare the connected platform against how you actually operate. A free tool for analyzing individual email files is a different workflow from running protection across every mailbox.
How to choose email security software
Match the deployment to your mail environment
Write down the mail platforms, shared mailboxes and hybrid systems that need protecting. Then separate three things a product might do: watch messages, block them before delivery, or pull them back after. Ask what the tool can actually see and change in each of those environments, including internal messages and malicious calendar invitations, because an API label on its own answers none of that.
Walk through response and restoration
Take a suspicious invoice, a legitimate account-change request and a message a user reported, and follow each one through the full workflow. Check how the tool surfaces related messages, what it does without a human, and how someone reverses a wrong call. A usable response process matters as much as sharp detection, and it’s the part a demo tends to gloss over.
Decide how much to consolidate
If the same team also runs training, manages the software employees install and watches AI usage, bring those needs into the decision rather than solving them later. This is where Noon’s wider scope helps, since inbox protection sits next to those controls and the practice for the people being targeted. A focused email product is the right answer too, when those other layers are already handled well elsewhere.
Price what you’ll actually operate
Compare the full configuration, including any training, support, retention and outbound controls you need, and count the migration work and ongoing administration, not just the license. Free mailbox scans and demos help establish fit, but the contract is what has to describe the services and limits you’ll live with.
Protect employees across the whole working day
The inbox is one of the best places to stop an attack, but it isn’t the only place one happens. The same employee who spots a bad email still installs software, connects an AI tool to company data and has to make a call when a plausible request arrives by phone instead. Protecting them means accounting for all of that, not just the message that reached their inbox.
Noon brings those responsibilities into one platform, so the team defending the inbox is also the team watching the devices and the AI tools, working from one picture instead of four. Book a Noon Security demo to see the email protection, device controls and AI governance together, or request early access.
