Email remains one of the most important communication channels for businesses. Employees use it to exchange documents, approve payments, communicate with customers, and coordinate everyday operations.
Unfortunately, attackers rely on email for many of the same reasons.
A convincing message can persuade an employee to reveal credentials. A fraudulent invoice may redirect a legitimate payment. A malicious attachment can introduce malware into an organization.
Modern email attacks are not always easy to recognize. Some contain no suspicious attachment or obvious malicious link. Others imitate legitimate business conversations or originate from compromised accounts.
Email Security Tools help organizations identify, investigate, and reduce these threats.
Choosing the right solution requires understanding the different forms of email attacks and the protection capabilities available.
What Are Email Security Tools?
Email Security Tools are technologies designed to protect email systems, users, and business communications against malicious or unauthorized activity.
They may provide capabilities such as:
- Spam and phishing detection
- Malicious attachment analysis
- URL inspection
- Business email compromise detection
- Impersonation protection
- Email authentication analysis
- Malware filtering
- Suspicious message investigation
- Post-delivery threat removal
- Outbound data protection
- Security awareness integration
Some tools operate as secure email gateways, while others connect directly to cloud email services through APIs.
Certain products combine multiple approaches.
The appropriate solution depends on the organization’s email infrastructure, threat exposure, and existing security controls.
Why Email Remains a Major Security Risk
Email is effective for attackers because it combines technical systems with human decision-making.
An attacker does not always need to exploit a software vulnerability.
Sometimes, persuading an employee to take an unsafe action is enough.
Phishing
Phishing messages attempt to deceive recipients into revealing information, opening malicious content, or visiting fraudulent websites.
Business Email Compromise
Business Email Compromise (BEC) involves impersonation or misuse of business communications to facilitate fraud or unauthorized activity.
An attacker may pretend to be an executive, supplier, or trusted employee.
Malware delivery
Malicious files or links may be used to deliver malware.
Credential theft
Fake login pages can imitate legitimate services and capture usernames, passwords, or other authentication information.
Account takeover
A compromised mailbox can be used to send convincing messages to colleagues and external contacts.
Data leakage
Employees may accidentally send confidential information to unintended recipients.
These threats require a combination of email security technology, identity protection, operational procedures, and user awareness.
How Email Security Tools Work
Message inspection
Email security systems evaluate incoming messages using available content, sender information, attachments, links, and other signals.
Sender authentication
Security controls can examine whether messages align with established email authentication mechanisms.
Threat intelligence
Some products use known malicious domains, addresses, file indicators, and other threat information to support detection.
Behavioral analysis
More advanced systems may evaluate communication patterns and unusual sender or recipient behavior.
Attachment analysis
Suspicious files may be examined using static analysis, sandboxing, or other techniques.
URL protection
Security systems may evaluate links before delivery or when a recipient attempts to open them.
Post-delivery remediation
Some products can identify and remove malicious messages after they have reached user mailboxes.
No single detection method is sufficient for every email threat.
Effective protection generally combines multiple signals and controls.
Email Security Tools Worth Evaluating
The following products represent different approaches to business email security.
1. Microsoft Defender for Office 365
Microsoft Defender for Office 365 provides email and collaboration security capabilities within supported Microsoft 365 environments.
Its features can include phishing protection, malicious attachment analysis, URL protection, investigation, and automated response capabilities, depending on licensing and configuration.
Best suited for: Organizations using Microsoft 365 and Exchange Online.
Key considerations: Licensing plans, policy configuration, investigation workflows, and integration with existing Microsoft security tools.
2. Proofpoint Email Protection
Proofpoint provides enterprise email security capabilities focused on identifying and reducing email-based threats.
Its broader portfolio includes technologies relevant to phishing, impersonation, malware, and user-focused security risks.
Best suited for: Enterprises with advanced email threat protection requirements.
Key considerations: Product components, deployment model, integration with the email platform, and operational complexity.
3. Mimecast Email Security
Mimecast provides email security capabilities designed to protect business communications against malicious messages and related threats.
Its offerings may include email threat detection, policy enforcement, and additional email resilience capabilities.
Best suited for: Organizations seeking dedicated email security controls.
Key considerations: Supported email environments, deployment options, policy management, and feature packaging.
4. Abnormal AI
Abnormal AI focuses on detecting email and collaboration-related threats using behavioral and contextual analysis.
Its approach is particularly relevant to attacks involving impersonation, social engineering, and compromised accounts.
Best suited for: Organizations concerned about sophisticated phishing and business email compromise.
Key considerations: Integration coverage, detection explainability, response workflows, and performance against representative attacks.
5. Check Point Harmony Email & Collaboration
Check Point Harmony Email & Collaboration provides security capabilities for supported cloud email and collaboration environments.
Its capabilities address threats involving malicious content, phishing, and other collaboration-related risks.
Best suited for: Organizations seeking protection across supported cloud communication services.
Key considerations: Platform compatibility, deployment requirements, security policy controls, and licensing.
6. Barracuda Email Protection
Barracuda provides email security capabilities designed to address phishing, malware, impersonation, and related email threats.
Its broader offerings may include additional email protection and resilience functions.
Best suited for: Small and midsize businesses as well as enterprises seeking managed email security capabilities.
Key considerations: Product tier, supported email platforms, administrative requirements, and incident response features.
7. Cisco Secure Email
Cisco Secure Email provides email threat protection capabilities for enterprise environments.
Its security controls address malicious messages, spam, and other email-borne threats.
Best suited for: Organizations with established enterprise email security requirements.
Key considerations: Deployment architecture, cloud integration, policy administration, and compatibility with existing security operations.
Comparing Email Security Platforms
| Platform | Primary emphasis | Evaluation priority |
|---|---|---|
| Microsoft Defender for Office 365 | Microsoft email and collaboration security | Licensing and native integration |
| Proofpoint Email Protection | Enterprise email threat protection | Threat detection and response |
| Mimecast Email Security | Dedicated email security | Policy coverage and deployment |
| Abnormal AI | Behavioral email threat detection | BEC and impersonation analysis |
| Check Point Harmony Email & Collaboration | Cloud communication security | Supported collaboration services |
| Barracuda Email Protection | Business email protection | Administration and product scope |
| Cisco Secure Email | Enterprise email security | Infrastructure and policy integration |
These platforms differ in detection methods, deployment architecture, and supported environments.
Organizations should evaluate them against realistic threat scenarios rather than assuming that every product offers the same capabilities.
Secure Email Gateway vs. API-Based Email Security
Two common approaches are secure email gateways and API-based email security.
Secure Email Gateway
A secure email gateway typically inspects messages as they pass through the email delivery path.
It may provide filtering, policy enforcement, and threat detection before messages reach recipients.
Gateway deployment can require mail-routing changes and ongoing configuration.
API-Based Email Security
API-based tools connect to supported cloud email services through authorized interfaces.
They can examine mailbox information and support detection or remediation within the capabilities provided by the email platform.
Some products can analyze messages after delivery or use platform-specific mechanisms to intervene earlier.
Which approach is better?
Neither approach is universally superior.
Gateway-based systems may provide strong inline controls.
API-based products can offer useful mailbox context and integration with cloud email environments.
Some organizations use both approaches.
The decision should reflect the email platform, threat model, deployment constraints, and required response capabilities.
Understanding Email Authentication
Email authentication helps receiving systems evaluate whether messages are authorized to use a particular sending domain.
Three important technologies are SPF, DKIM, and DMARC.
SPF
Sender Policy Framework identifies which mail servers are authorized to send messages for a domain.
DKIM
DomainKeys Identified Mail uses cryptographic signatures to help verify that signed message content has not been improperly altered and is associated with the signing domain.
DMARC
Domain-based Message Authentication, Reporting and Conformance builds on SPF and DKIM alignment to help domain owners establish handling policies and receive authentication reports.
These controls are important, but they do not eliminate phishing.
An attacker may use a legitimate-looking domain, a compromised account, or a properly authenticated domain under their own control.
Email authentication should be part of a broader security strategy.
Detecting Business Email Compromise
BEC attacks can be difficult to identify because they may contain no malware or suspicious link.
A fraudulent message might simply request a payment change or confidential document.
Detection may require examining:
- Sender identity
- Communication history
- Unusual payment requests
- Message language and context
- Account behavior
- Reply-to addresses
- Domain similarities
- Unexpected changes in established workflows
Technical controls should be supported by business procedures.
For example, payment account changes should be verified through an established independent communication channel.
A security product cannot replace sound financial approval controls.
Essential Email Security Features
Phishing and impersonation detection
The platform should identify suspicious messages that imitate trusted people or organizations.
Attachment protection
Evaluate support for malicious file detection and appropriate analysis techniques.
URL analysis
The platform should address suspicious links and relevant post-delivery risks.
Account compromise visibility
Some products provide signals that help identify suspicious mailbox activity.
Incident response
Security teams need efficient ways to investigate and remove confirmed malicious messages.
Reporting and visibility
Useful reports should distinguish real security threats from routine spam.
Integration
Email security should connect appropriately with identity systems, security operations, and incident response workflows.
How to Choose Email Security Tools
Begin by identifying the organization’s email infrastructure.
Determine whether the primary environment is Microsoft 365, Google Workspace, an on-premises email system, or a combination.
Next, review existing protection.
Many organizations already have email filtering and authentication capabilities but may lack advanced impersonation detection or post-delivery response.
Identify the most important threat scenarios.
For example, a financial services company may prioritize BEC and payment fraud, while a business handling sensitive intellectual property may also emphasize outbound data protection.
Evaluate products using representative examples and carefully controlled tests.
Review administrative effort, integration requirements, privacy considerations, and total cost.
Finally, ensure that the platform provides useful investigation information rather than simply generating additional alerts.
Common Email Security Mistakes
Relying entirely on spam filtering
Spam filtering is important but does not address every form of impersonation or account compromise.
Ignoring identity security
Multifactor authentication, secure account recovery, and access monitoring remain essential.
Treating email authentication as complete protection
SPF, DKIM, and DMARC help establish domain authenticity but cannot prevent every phishing attempt.
Overlooking outbound email
Sensitive information can be disclosed through legitimate employee accounts.
Failing to investigate delivered threats
Some malicious messages may initially bypass filtering.
Post-delivery investigation and remediation can reduce their impact.
Neglecting employee reporting
Employees need a simple way to report suspicious messages.
Building an Effective Email Security Program
Start by reviewing the email environment and existing security controls.
Configure appropriate domain authentication.
Apply phishing, malware, and impersonation protection policies.
Establish secure procedures for sensitive business actions such as payment changes.
Provide employees with practical guidance on recognizing and reporting suspicious messages.
Integrate email alerts with security investigation workflows.
Test incident response procedures, including the ability to identify and remove malicious messages.
Review trends and adjust controls regularly.
The objective is to reduce successful email attacks while maintaining reliable communication.
Measuring Email Security Effectiveness
Useful metrics include:
- Confirmed phishing incidents
- Malicious messages reaching user inboxes
- Time to investigate reported messages
- Time to remove confirmed malicious email
- Business email compromise incidents
- Employee reporting rates
- False-positive detection rates
- Email authentication coverage
These measurements should be considered together.
A high number of blocked messages does not necessarily demonstrate that an organization is well protected against sophisticated attacks.
Frequently Asked Questions
Does Microsoft 365 include email security?
Microsoft 365 includes various email security capabilities, with additional features available through relevant Microsoft Defender plans. Organizations should verify their specific licenses and configuration.
Can email security tools prevent business email compromise?
They can help detect and reduce BEC threats, but financial verification procedures, identity protection, and employee awareness remain necessary.
Is a secure email gateway necessary for cloud email?
Not always. Cloud email platforms and API-based security products may provide sufficient controls for some organizations. Requirements depend on the threat model and existing protection.
Do email security tools protect against compromised accounts?
Some products provide relevant detection and response capabilities, but account protection also requires identity security and access monitoring.
Is email security training still important?
Yes. Technical controls can reduce threats, while practical training and reporting procedures help employees respond to suspicious messages.
Conclusion
Email Security Tools protect one of the most widely used and frequently targeted business communication channels.
Microsoft Defender for Office 365, Proofpoint, Mimecast, Abnormal AI, Check Point, Barracuda, and Cisco offer different approaches to detecting and managing email threats.
The right solution depends on the organization’s email infrastructure, exposure to phishing and business email compromise, and existing security capabilities.
Effective email protection combines strong technical detection with identity security, operational verification procedures, and reliable incident response.
The goal is not simply to block more messages. It is to make business communication safer without reducing its usefulness.