Email Security Risk Assessment: How to Audit Your Email Defenses

An email security risk assessment is a structured evaluation of your authentication configuration, gateway filtering, access controls, and employee susceptibility, designed to identify and prioritize vulnerabilities before attackers exploit them. It goes beyond simply having tools deployed to verifying they actually work.

If you deployed email security tools two years ago and have never checked whether they are still configured correctly, or your cyber insurance renewal is asking for evidence of a recent assessment and you have nothing to show, this guide gives you a genuine path forward. It includes free tools you can use right now, and an honest account of what those tools cannot tell you.

What Is an Email Security Risk Assessment?

An email security risk assessment is a structured evaluation of an organisation’s email infrastructure, configuration, tooling, and employee behaviour to identify vulnerabilities and gaps that could be exploited by attackers. Internal IT teams or external specialists can conduct it.

This is different from a checklist. A checklist is a static list of recommended controls. An assessment is the active, evidence-based process of testing whether those controls are actually in place, correctly configured, and functioning as intended in your specific environment right now.

“We have email security tools” and “we have assessed our email security” are two fundamentally different claims, and most organisations conflate them without realising it. Deployment is a one-time event: a gateway was configured, MFA was enabled, a DMARC record was published, sometime in the past. Assessment is an ongoing verification process confirming those controls are still correctly configured and functioning as intended right now.

This distinction matters because tools drift silently after deployment. New staff are onboarded with inconsistent permissions. New third-party tools get OAuth access to email accounts without anyone reviewing whether that access remains appropriate. Policies get adjusted reactively in response to a specific complaint, without anyone checking whether the adjustment weakened the broader security posture. None of this shows up unless someone actively checks. A DMARC record published two years ago at p=quarantine might still technically exist while nobody has reviewed the aggregate reports in eighteen months, meaning new authorised sending services added since then may be silently failing authentication, or, worse, the policy may have quietly been weakened to p=none by someone troubleshooting a delivery issue. The tools being in place and the tools actually working as intended right now are different claims, and only an assessment, not a memory of the original deployment, can verify which one is currently true.

Why Should You Conduct a Regular Email Security Health Check?

Configuration drift happens continuously. Settings change as new staff onboard, new third-party tools integrate, and policies get adjusted reactively, often without a corresponding review of whether the overall security posture remains sound.

The threat landscape changes faster than most organisations review their defences. New attack techniques like quishing and AI-generated phishing emerge regularly, and controls considered adequate two years ago may no longer address current risks. Regulatory frameworks and cyber insurance underwriters increasingly expect evidence of regular assessment, not just initial deployment. Without an assessment, security spending decisions are often based on vendor sales pitches or anecdotal incidents rather than evidence of actual risk.

What Does an Email Security Risk Assessment Examine?

A complete assessment examines:

• Email authentication configuration: SPF, DKIM, and DMARC presence, correctness, and enforcement level
• Gateway and filtering effectiveness: whether spam, phishing, and malware filtering is correctly configured and performing as expected
• Access control and identity: MFA coverage across all accounts, legacy authentication protocols that bypass MFA, and privileged account review
• Encryption status: whether TLS is enforced for email in transit and sensitive communications use appropriate end-to-end encryption
• Data loss prevention configuration: whether DLP policies exist and are tuned for the organisation’s sensitive data types
• Policy and governance documentation: whether a formal email security policy exists, is current, and has been communicated to staff
• Employee susceptibility: measured through phishing simulation results
• Incident response readiness: whether a documented process exists for responding to confirmed incidents

See Email Security Best Practices: The Definitive 2026 Checklist for the full control set this assessment verifies.

How Do You Check Your Email Authentication Configuration?

Check authentication in three steps. First, verify a valid SPF record exists, includes all legitimate sending services, and uses an appropriate qualifier (~all or -all). Second, confirm DKIM signing is enabled and the public key is correctly published in DNS. Third, verify a DMARC record exists, check the current policy level (none, quarantine, or reject), and review whether aggregate reports are being actively monitored.

Free tools for this check include MXToolbox for SPF, DKIM, and DMARC checking, Google Postmaster Tools for Gmail-bound mail reputation and authentication pass rates, and dmarcian for dedicated DMARC reporting. What good looks like: fully configured SPF and DKIM, DMARC at minimum p=quarantine with active monitoring of aggregate reports, ideally progressing toward p=reject. See SPF, DKIM and DMARC Explained for the full configuration detail.

How Do You Test Your Email Security Gateway and Filtering Effectiveness?

Test gateway effectiveness by reviewing quarantine logs and false positive and negative rates over a defined period to assess whether filtering is correctly tuned. Check whether outbound filtering is enabled, not just inbound, a frequently overlooked gap. Verify attachment sandboxing is active for unrecognised file types. Confirm time-of-click URL re-scanning is enabled rather than delivery-time-only scanning, and review whether high-risk attachment types are appropriately restricted.

Employee-facing phishing simulation and controlled authorised simulated delivery testing against the gateway itself are frequently conflated under a single “phishing simulation” label, but they measure entirely different things. Employee phishing simulation tests human behaviour: will a person click a link, enter credentials, or report a suspicious email. It tells you nothing about whether your technical filtering layer would have blocked the same email if it had been a genuine attack rather than an authorised test sent specifically to bypass simulation-aware filtering rules.

Controlled, authorised simulated delivery testing is a distinct technical exercise, conducted with appropriate authorisation and typically through specialist tooling, that sends realistic but safe test payloads through your actual mail flow to verify whether your gateway, sandboxing, and filtering rules catch what they are configured to catch. This tests the technical layer independent of any human factor entirely. An organisation can have excellent employee phishing simulation results while having a gateway with a significant, completely separate filtering gap that nobody has verified, because the employee test was never designed to validate the technical layer in the first place. A genuinely complete assessment runs both tests, treats them as answering different questions, and does not assume strong performance on one indicates strength on the other. See What Is a Secure Email Gateway (SEG)? and Email DLP: How to Prevent Data Leaks Through Email for the underlying architecture this testing validates.

How Do You Assess Employee Susceptibility to Email-Based Attacks?

Phishing simulation is the primary measurement tool. Running realistic, varied simulated phishing campaigns and measuring click-through and report rates provides the clearest behavioural risk data available. Benchmark results against industry data, such as the KnowBe4 Phishing Industry Benchmarking Report, to contextualise whether your organisation’s susceptibility is above, at, or below typical levels for your sector and size.

Reporting behaviour deserves weight as a risk-modifying factor alongside click-through rate, a nuance flat susceptibility scoring consistently misses. Consider two organisations with identical 15 percent click-through rates on a simulation campaign. In the first, employees who clicked reported it themselves within minutes, and the broader workforce reports suspicious email promptly and consistently. In the second, employees who click rarely report it, either out of embarrassment or because no clear reporting habit exists. These two organisations do not carry equal risk, even though the click-through number is identical. The first organisation has a genuine early-warning capability that limits how far a real attack can spread before detection. The second has a population that, when it makes a mistake, makes it silently, giving an attacker far more time to act before anyone notices.

The reverse case matters equally. An organisation with an excellent five percent click-through rate but very poor reporting behaviour, where suspicious emails simply get deleted rather than reported, may have a false sense of security. Low click rates feel reassuring, but if genuine reporting habits are weak, the organisation has no real visibility into ongoing attack campaigns targeting it, and no operational mechanism to contain a successful attack quickly when one eventually succeeds. Department and role segmentation should be applied alongside this: an aggregate organisation-wide score can mask a dangerously high result concentrated specifically in finance or executive roles, exactly where BEC targeting is most damaging, even while the overall number looks acceptable. See Phishing Simulation Campaigns: How to Test and Train Your Team for the full simulation mechanics.

What Free Tools Can You Use to Check Your Email Security Right Now?

Tool	What It Checks	Cost	Output Type
MXToolbox	SPF, DKIM, DMARC, blacklist status, MX records	Free	Pass/fail report with detail
Google Postmaster Tools	Domain reputation, authentication pass rates (Gmail)	Free	Dashboard over time
Mail Tester	Authentication, content, deliverability score	Free (limited tests)	Numeric score with breakdown
dmarcian (free tier)	DMARC report parsing and visualisation	Free tier available	Aggregate report summary
Have I Been Pwned (domain search)	Email addresses in known breaches	Free	List of exposed addresses
Microsoft Secure Score / Google Workspace Security Health	Platform configuration vs recommended baseline	Free (built into admin console)	Numeric score with recommendations

This combination of named, specific, genuinely free tools lets a reader complete a meaningful technical self-check within an hour, with no paid engagement required. Run MXToolbox first to confirm SPF, DKIM, and DMARC are correctly published. Check Google Postmaster Tools if a meaningful proportion of your mail goes to Gmail recipients, since it reveals authentication pass rates from the receiving side, not just whether records exist. Run Mail Tester for an independent deliverability score. Check Have I Been Pwned against your domain to understand existing credential exposure risk. Finally, review Microsoft Secure Score or Google Workspace Security Health directly in your admin console for a built-in configuration baseline comparison.

Being honest about what these free checks cannot reveal matters as much as recommending them. They cannot assess whether your email security policy is current and has been acknowledged by staff. They cannot measure employee susceptibility, which requires an actual phishing simulation campaign. They cannot detect configuration drift that happened gradually over time unless you specifically compare results against a previous baseline check. And they cannot evaluate incident response readiness, which requires reviewing documented processes rather than scanning DNS records. Free tools genuinely answer the technical configuration question well. They do not answer the behavioural, governance, or readiness questions a comprehensive assessment covers, and treating a clean MXToolbox result as proof of complete email security coverage is a common and risky misreading of what these tools actually validate.

How Do You Score and Prioritize the Risks You Identify?

Use a simple likelihood-and-impact framework to prioritise findings rather than attempting to fix everything simultaneously.

Finding Type	Example	Priority Level	Recommended Timeframe
Authentication enforcement gap	DMARC at p=none or absent	High	Within 2-4 weeks
Access control gap	MFA missing on any account	High	Immediately
Filtering gap	No outbound filtering or DLP	High	Within 4-6 weeks
Governance gap	No documented incident response process	High	Within 4-6 weeks
Suboptimal configuration	Functional but not fully tuned authentication	Medium	Within 1-3 months
Documentation gap	Inconsistent policy documentation	Medium	Within 1-3 months
Behavioural risk	Moderate phishing simulation susceptibility	Medium	Ongoing, tied to training cadence
Cosmetic gap	Efficiency-related, non-exploitable issue	Low	When resourced

Document findings formally, even an internally conducted assessment benefits from a written summary that can inform budget conversations, track progress over time, and demonstrate due diligence to auditors or insurers. Cyber Security Solutions Ltd applies a structured likelihood-and-impact scoring methodology, aligned with NIST SP 800-30 risk assessment principles, when conducting comprehensive email security assessments for clients.

How Often Should You Conduct an Email Security Risk Assessment?

Step 1: Check email authentication configuration (SPF, DKIM, DMARC).

Step 2: Review gateway and filtering configuration and quarantine logs.

Step 3: Audit access control and MFA coverage across all accounts.

Step 4: Run a phishing simulation to measure employee susceptibility.

Step 5: Review policy documentation and incident response readiness.

Step 6: Score and prioritise findings by likelihood and impact.

Step 7: Document findings and schedule the next review cycle.

Conduct a comprehensive formal assessment at minimum annually. Run lighter-touch technical checks of authentication status and MFA coverage quarterly using the free tools listed above. Trigger an assessment outside the normal cycle following major platform migration, a notable security incident, significant staff growth, or emergence of a new widely-reported attack technique relevant to your sector. Position assessment as a continuous discipline rather than a one-time project, tying naturally into the regular review cadence recommended for your email security policy.

Conclusion

Free tools give you a genuine, immediate starting point for checking your technical configuration today, but they cannot tell you whether your employees would fall for a targeted BEC attempt or whether your incident response plan actually works under pressure. Real protection requires both layers assessed together. Visit cybersecuritysolutionsltd.com for a free, comprehensive email security assessment from our team that goes beyond what self-service tools can reveal, including employee susceptibility testing and policy review.