RepMail Resource Center
Getting StartedCold EmailDeliverabilityOutreachEmail InfrastructureEmail Sending PlatformGlossary
RepMail
  1. RepMail Resource Center
  2. Email Authentication Essentials
Collection

Email Authentication Essentials

Everything that proves your mail is really yours: the authentication overview, each of SPF, DKIM, and DMARC in depth, and the DNS records they live in.

5 guides

The Complete Guide to Email Authentication

How SPF, DKIM, DMARC, and the newer ARC and BIMI standards prove your mail is really yours, and why cold email fails without them.

Knowledge base·2 min read·Deliverability & Sender Reputation

What Is an SPF Record, and How Do You Set It Up?

SPF is a DNS record listing the servers allowed to send as your domain. Here is how it works, how to set it, and the mistakes that break it.

Glossary·2 min read·Deliverability & Sender Reputation

What Is DKIM, and Why Does It Matter for Cold Email?

DKIM cryptographically signs every message you send so receivers can prove it is really from you and was not altered. Here is how to set it up.

Glossary·2 min read·Deliverability & Sender Reputation

What Is DMARC, and Which Policy Should You Use?

DMARC tells receivers what to do when SPF or DKIM fails, and reports who sends mail in your name. Here is how to roll it out without blocking yourself.

Glossary·2 min read·Deliverability & Sender Reputation

DNS Records for Email: MX, PTR, SPF, DKIM, and DMARC

Every deliverability check starts in your DNS. Here is what each email record does, MX, PTR, SPF, DKIM, DMARC, and how they work together.

Knowledge base·2 min read·Email Infrastructure
RepMail Resource Center
All guidesProductPricingChangelogContact