Email was not originally designed with strong identity verification. That is why spoofing is still common. Attackers can make emails appear to come from trusted domains unless the domain owner sets proper authentication controls.

SPF, DKIM, and DMARC are three DNS-based protections that help reduce spoofing.

SPF stands for Sender Policy Framework. It tells the world which mail servers are allowed to send email for your domain. If a message comes from a server not listed in your SPF record, receivers may treat it as suspicious.

DKIM stands for DomainKeys Identified Mail. It adds a cryptographic signature to outgoing email. The receiving server checks the signature against a public key in DNS. If the message was changed or not signed correctly, DKIM fails.

DMARC stands for Domain-based Message Authentication, Reporting, and Conformance. It builds on SPF and DKIM. DMARC tells receivers what to do when authentication fails and sends reports back to the domain owner.

A basic DMARC policy may start with monitoring:

p=none

This lets you collect reports without blocking mail. After reviewing legitimate senders, you can move to stronger policies:

p=quarantine

Then eventually:

p=reject

The goal is to stop unauthorized senders from pretending to be your domain.

Common mistakes include:

Too many SPF lookups
Missing third-party senders
DKIM not enabled on mail platforms
DMARC stuck forever at p=none
No reporting address
Misaligned domains

For small businesses, email authentication is one of the best anti-phishing investments. It protects customers, employees, and brand reputation.

NeoShield recommends auditing DNS records regularly, especially after adding new email tools such as newsletters, CRMs, helpdesks, invoicing systems, or marketing platforms.

If your domain sends email, SPF, DKIM, and DMARC are not optional anymore. They are basic domain hygiene.