DNS Authentication Protocols for Email Deliverability: An Overview

Email authentication is a collaborative process between your ESP, IT team, and marketing department. This is necessary to verify the identity of senders and prevent hijacking of your email domain.

Proper authentication builds trust with recipients, reduces spam and phishing risks, and confirms the legitimacy of your email program. As a result, this increases trust in your brand and higher engagement.

DNS Authentication Protocol

SPF (Sender Policy Framework)

SPF is often the first authentication method to be configured. It allows domain owners to specify which IP addresses are authorized to send email on behalf of their domain.

DKIM (DomainKeys Identified Mail)

It provides verifiable proof that an email truly came from your organization. When sending, your Mail Transfer Agent (MTA) adds a unique DKIM signature header to each email. 

DMARC (Domain-based Message Authentication, Reporting, and Conformance)

It tells receiving mail servers how to handle emails that fail authentication (reject, quarantine, or allow).

BIMI (Brand Indicators for Message Identification)

BIMI is a newer standard that requires DMARC implementation to display verified logos in recipients’ inboxes. The goal is to boost trust, improve brand recognition, and help emails stand out in crowded inboxes.