DNS & Email Learning Center

Plain-language guides on SPF, DKIM, DMARC, MX priority, reverse DNS, propagation, and email deliverability — each paired with the matching free bulk tool.

What Is an SPF Record? Complete Guide

SPF (Sender Policy Framework) is a DNS TXT record that lists which mail servers are allowed to send email on b…

What Is DKIM? How Email Signing Works

DKIM (DomainKeys Identified Mail) is an email authentication method that lets a sending domain digitally sign …

What Is DMARC? How to Fix a DMARC Fail

DMARC (Domain-based Message Authentication, Reporting & Conformance) is a DNS TXT record that tells receiving …

MX Record Priority Explained

An MX (Mail Exchanger) record tells the internet which mail server(s) handle email for a domain. A domain can …

What Is a PTR Record? Reverse DNS Explained

A PTR (Pointer) record does the opposite of a normal DNS lookup — instead of resolving a domain name to an IP …

How Long Does DNS Propagation Take?

DNS propagation is the time it takes for a DNS change — like updating an A record or switching nameservers — t…

Why Is My Email Going to Spam? 7 Common Causes

If your emails are landing in spam folders instead of the inbox, it's almost always one (or several) of a hand…