---
title: "Email Security Checker"
description: "Verify email domain security configuration including SPF, DKIM, DMARC, MTA-STS, TLS-RPT, and BIMI. Get a comprehensive security assessment for your email infrastructure."
url: https://findutils.com/security/email-security-checker/
category: security
---

# Email Security Checker

Verify email domain security configuration including SPF, DKIM, DMARC, MTA-STS, TLS-RPT, and BIMI. Get a comprehensive security assessment for your email infrastructure.

**Use this tool:** [Email Security Checker](https://findutils.com/security/email-security-checker/)

## Programmatic access

- REST id `email-security-checker`: POST https://api.findutils.com/api/tools/email-security-checker/execute (reference: https://findutils.com/api/email-security-checker/)
- MCP tool `email_security_checker` on https://mcp.findutils.com (reference: https://findutils.com/mcp/email-security-checker/)

## Why Check Email Security?

Email remains the primary vector for cyberattacks. Proper security configuration protects your organization from phishing, spoofing, and ensures email deliverability.

## Email Security Best Practices

- Always publish an SPF record that includes all legitimate sending sources, and end with '-all' to hard-fail unauthorized senders.
- Rotate DKIM signing keys at least once per year. Use 2048-bit RSA keys or stronger to resist brute-force attacks.
- Start with a DMARC policy of 'p=none' to collect reports, then gradually move to 'p=quarantine' and finally 'p=reject' once you confirm legitimate mail passes authentication.
- Enable MTA-STS to enforce TLS encryption between mail servers. This prevents man-in-the-middle downgrade attacks during email transit.
- Set up TLS-RPT (TLS Reporting) so you receive notifications when other mail servers fail to establish encrypted connections with your domain.

## Frequently Asked Questions

### What is MTA-STS?

Mail Transfer Agent Strict Transport Security (MTA-STS) enforces TLS encryption for email delivery, preventing downgrade attacks.

### What is TLS-RPT?

TLS Reporting (TLS-RPT) provides reports about TLS connection failures, helping you identify and fix email delivery issues.

### What is BIMI?

Brand Indicators for Message Identification (BIMI) displays your logo next to authenticated emails, increasing trust and visibility.

### How do I improve my score?

Start with SPF, DKIM, and DMARC. Once these are configured, add MTA-STS and TLS-RPT for encryption, then consider BIMI for branding.

### What is SPF and why does my domain need it?

Sender Policy Framework (SPF) is a DNS TXT record that specifies which mail servers are authorized to send email on behalf of your domain. Without SPF, attackers can forge the From address in emails, making phishing attempts appear legitimate.

### What is DKIM and how does it work?

DomainKeys Identified Mail (DKIM) adds a cryptographic signature to outgoing emails. The receiving server verifies this signature against a public key published in your DNS records, confirming the message was not altered in transit and originated from an authorized sender.

### What is DMARC and how does it prevent email spoofing?

Domain-based Message Authentication, Reporting and Conformance (DMARC) builds on SPF and DKIM by telling receiving mail servers what to do when authentication fails. A DMARC policy of 'reject' instructs servers to block unauthenticated messages, effectively stopping spoofed emails from reaching inboxes.

### How often should I check my email security configuration?

You should audit your email security records at least once per quarter, or immediately after changing DNS providers, email services, or mail server infrastructure. Misconfigured records can silently break email delivery or weaken spoofing protection.

### Can this tool check any domain or only my own?

You can check any domain. SPF, DKIM selectors, DMARC, MTA-STS, TLS-RPT, and BIMI records are all published in public DNS. This is useful for verifying partner or vendor email security posture before exchanging sensitive information.

### Does a perfect score guarantee my emails will not be spoofed?

A high score significantly reduces the risk but does not eliminate it entirely. Email security is layered: SPF, DKIM, and DMARC handle authentication and policy, while MTA-STS enforces encryption in transit. Maintaining all layers current and correctly configured is the best defense.

## Related Tools

- [DNS Security Scanner](https://findutils.com/network/dns-security-scanner/)
- [SSL Certificate Checker](https://findutils.com/network/ssl-certificate-checker/)
- [Security Headers Analyzer](https://findutils.com/network/security-headers-analyzer/)
- [Email Validator](https://findutils.com/security/email-validator/)
- [DNS Lookup](https://findutils.com/network/dns-lookup/)
- [URL Safety Checker](https://findutils.com/security/url-safety-checker/)
- [Privacy Policy Checker](https://findutils.com/security/privacy-policy-checker/)
- [IP Address Lookup](https://findutils.com/network/ip-address-lookup/)