What is the Cyber Defense Score™?

The Cyber Defense Score™ is an A–F letter grade plus a 0–100 numerical score produced by a 100-tool external attack surface scan. It shows you exactly what cyber insurance underwriters see when they assess your business. It is mapped to NIST CSF 2.0, CIS Controls, SOC 2, NIST 800-171, FTC Safeguards Rule, and PCI-DSS readiness.

How does Cyber Defense Agent help with cyber insurance?

Cyber Defense Agent runs the same external scans that cyber insurance underwriters use to assess your risk. By scanning first, you can identify and fix gaps (missing MFA, DMARC, open ports, SSL issues) BEFORE your renewal or new application. This helps you avoid denials, reduce premiums, and pass underwriting on the first attempt.

What do cyber insurance underwriters scan for?

Underwriters typically scan for: MFA enforcement across all remote access, DMARC/SPF/DKIM email authentication, open RDP ports (3389), SSL/TLS configuration, known vulnerabilities in public-facing services, DNS security, and evidence of endpoint detection (EDR). Cyber Defense Agent checks all of these in 60 seconds.

Can Cyber Defense Agent help me lower my cyber insurance premium?

Yes. Carriers offer premium discounts of 10–25% for businesses that demonstrate strong security posture. By fixing the gaps Cyber Defense Agent identifies and presenting your Cyber Defense Score™ and trust page to your broker, you provide concrete evidence of risk reduction that carriers reward with lower premiums.

Why was my cyber insurance application denied?

The most common denial reasons are: no MFA on email and remote access (41% of denials), missing DMARC email authentication, open RDP ports, no EDR/endpoint protection, and no incident response plan. Cyber Defense Agent scans for all of these and shows you exactly what to fix before reapplying.

How long does a Cyber Defense Agent scan take?

A full 100-tool external attack surface scan completes in approximately 60 seconds. No software installation, no questionnaires, and no credit card is required to get started. You see the same view of your attack surface that underwriters see.

What frameworks does Cyber Defense Agent map to?

Cyber Defense Agent maps scan results to NIST CSF 2.0, CIS Controls, SOC 2, NIST 800-171, FTC Safeguards Rule, and PCI-DSS readiness. These are the same frameworks cyber insurance carriers reference in their underwriting guidelines.

How much does Cyber Defense Agent cost?

Essentials starts at $149/mo ($1,490/yr). Pro is $349/mo ($3,490/yr) and includes internal scanning, SOC 2 readiness, and full MCP toolset. Enterprise is $999/mo ($9,990/yr) with daily scans, custom framework mapping, and a dedicated AI agent instance. MSP partners pay $79/business/mo with a 25-business minimum. The free scan is always free.

How do I prepare for cyber insurance renewal?

Start 60–90 days before renewal. Run a Cyber Defense Agent scan to identify gaps. Fix critical items: enforce MFA everywhere, deploy DMARC, close open ports, update EDR. Re-scan to verify improvements. Present your Cyber Defense Score™ and trust page to your broker as evidence of improved posture. This positions you for renewal without premium increases or coverage reductions.

What is a trust page?

A trust page is a public cybersecurity posture page hosted at trust.cyberdefenseagent.ai/{your-slug}. It displays your Cyber Defense Score™, framework compliance status, and last scan date. Brokers, underwriters, and business partners can verify your security posture in 60 seconds instead of reviewing 30-page questionnaires.

Definitive Guide

Email Authentication: SPF, DKIM & DMARC

Business email compromise (BEC) is the #1 cause of financial loss from cybercrime. SPF, DKIM, and DMARC are the three protocols that stop it. Cyber Defense Agent scans all three — here's how they work.

Farhad Mirza Khawar

Founder of HIPAA Agent and Cyber Defense Agent. Compliance infrastructure for SMBs. Sacramento, CA.

2026-05-01

Get My Cyber Defense Score™ →Book a 30-min review

In this guide

1. Why email authentication prevents BEC
2. How each protocol works
3. Implementation order and best practices

Why email authentication prevents BEC

Business email compromise (BEC) accounted for over $2.9 billion in losses in 2023 alone, making it the costliest category of cybercrime. BEC attacks work by spoofing a trusted sender's email address — impersonating a CEO, vendor, or attorney to trick employees into wiring funds or sharing sensitive data. Email authentication protocols — SPF, DKIM, and DMARC — work together to make spoofing your domain virtually impossible. When properly configured, receiving mail servers can verify that an email truly originated from your organization and hasn't been tampered with in transit. Cyber Defense Agent scans all three protocols as part of every domain assessment. Missing or misconfigured email authentication is one of the most common findings, and one of the easiest to fix.

How each protocol works

SPF (Sender Policy Framework) publishes a DNS TXT record listing the IP addresses and services authorized to send email on behalf of your domain. When a receiving server gets an email claiming to be from your domain, it checks your SPF record to verify the sending server is authorized. DKIM (DomainKeys Identified Mail) adds a cryptographic signature to every outgoing email. The sending server signs the message with a private key, and the receiving server verifies it using a public key published in your DNS. This proves the message wasn't altered in transit and truly came from your domain. DMARC (Domain-based Message Authentication, Reporting and Conformance) ties SPF and DKIM together with a policy that tells receiving servers what to do when authentication fails. DMARC also provides reporting so you can see who is sending email as your domain — both legitimate and fraudulent.

Implementation order and best practices

Implement email authentication in this order to avoid disrupting legitimate mail flow: 1. SPF first — Identify all services that send email as your domain (email provider, CRM, marketing tools, helpdesk). Create an SPF record listing all authorized senders. Test with online SPF validators. 2. DKIM second — Generate DKIM keys through your email provider. Publish the public key as a DNS CNAME or TXT record. Most providers (Microsoft 365, Google Workspace) make this straightforward. 3. DMARC last — Start with a policy of p=none to monitor without blocking. Review DMARC aggregate reports (rua) for 2-4 weeks to identify any legitimate senders you missed. Gradually move to p=quarantine, then p=reject. Common mistakes to avoid: - Forgetting third-party senders in your SPF record (marketing platforms, CRM systems) - Not rotating DKIM keys annually - Jumping straight to DMARC p=reject without a monitoring period - Having more than 10 DNS lookups in your SPF record (causes SPF failure)

Key Takeaways

TL;DR

BEC is the costliest cybercrime — email authentication is the primary defense.

SPF authorizes sending servers, DKIM signs messages cryptographically, DMARC enforces policy.

Implement in order: SPF first, then DKIM, then DMARC with gradual enforcement.

Cyber Defense Agent scans all three protocols and flags misconfigurations.

Start DMARC at p=none and monitor reports before moving to p=reject.

Official Sources

CISA BOD 18-01: Email Authentication DMARC.org Overview

FAQ

Frequently asked questions

Does Cyber Defense Agent check SPF, DKIM, and DMARC?

Yes. Every Cyber Defense Agent scan checks for the presence and correctness of SPF, DKIM, and DMARC records. The scan identifies missing records, misconfigured policies, and common errors like exceeding SPF lookup limits.

What is the difference between SPF, DKIM, and DMARC?

SPF verifies the sending server is authorized. DKIM verifies the message hasn't been tampered with using cryptographic signatures. DMARC ties them together with an enforcement policy (none, quarantine, or reject) and provides reporting on authentication results.

How long does it take to implement email authentication?

SPF and DKIM can each be configured in under an hour for most email providers. DMARC should be implemented over 4-6 weeks: start with monitoring (p=none), review reports, then gradually enforce. The technical setup is quick, but responsible DMARC enforcement requires a monitoring period.

Will email authentication break my legitimate email?

It can if implemented incorrectly. The most common issue is forgetting third-party services in your SPF record (marketing tools, CRM, helpdesk). This is why DMARC should start at p=none — it monitors without blocking, giving you time to identify and authorize all legitimate senders.

Related Guides

Continue reading

SPF Record Setup & Troubleshooting DKIM Implementation Guide DMARC Policy Configuration Guide

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