[ Quick answer ]
Email security is the set of controls that protect an organization from phishing, spoofing, business email compromise (BEC), malware and data loss through email. Domain-level protection starts with DMARC enforcement, SPF and DKIM, then adds MTA-STS for encryption, lookalike-domain monitoring and user awareness.
Key facts
- ›Phishing and BEC remain among the most costly cybercrime categories in FBI IC3 reporting.
- ›DMARC at p=reject blocks exact-domain spoofing of your brand.
- ›Lookalike domains bypass DMARC, so they need separate monitoring.
- ›MTA-STS prevents inbound mail being downgraded to unencrypted delivery.
Reviewed 2026-11-02 · EmailAuth research team
Most email attacks rely on trust in a sender. Attackers either spoof your exact domain, register a lookalike, or compromise a real mailbox. Each needs a different control.
Threats and controls
- Exact-domain spoofing: stopped by DMARC at p=reject.
- Lookalike and homoglyph domains: found by continuous domain monitoring and taken down.
- Downgrade and interception: prevented by MTA-STS with TLS-RPT.
- Subdomain takeover: prevented by removing dangling CNAME records.
- Account takeover: reduced by MFA and anomaly detection.
Start with your exposure
Run the free domain health scan and lookalike finder to see how easily your domain can be impersonated today.
Frequently asked questions
What is email spoofing?
Forging the From address so a message appears to come from a trusted domain. DMARC at p=reject stops spoofing of your exact domain.
How does DMARC prevent phishing?
It instructs receivers to reject messages that claim your domain but fail authentication, so attackers cannot send as you.
What is business email compromise?
A scam where attackers impersonate executives, suppliers or partners by email to trick staff into paying money or sharing data.
How does AI help email security?
EmailAuth's agentic AI watches every sender, spots spoofing and misconfigurations and prepares fixes around the clock, while your team approves policy changes. It runs as SaaS, on-premise or in your own cloud tenancy with your own AI key.
What is a lookalike domain?
A domain that resembles yours, such as a typo or a Unicode homoglyph, registered to impersonate you. Use a lookalike domain finder to discover them.
[ Email security guide ]
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