Why SPF, DKIM, and DMARC Matter More Than You Think

by:

Ben Myslenski

May 8, 2026

Most people don't know what these things (Dmarc, DKIM, SPF) are but they have a major role in your domain security and email deliverability.

SPF (Sender Policy Framework)

It tells the internet: Only these servers are allowed to send email for my company.

If someone not on the list tries to send email as you it blocks fake emails pretending to be you. What also helps is when this is properly setup email providers trust you more.

DKIM (DomainKeys Identified Mail)

Think of this like a tamper-proof seal on a letter.

When you send an email, it gets a hidden signature, the receiving server checks that signature to make sure the email really came from you and wasn’t changed along the way.

This stops people from changing your email and from a deliverability standpoint proves your email is legit

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

Think of this like a rule book + report card.

It tells email providers what to do if SPF or DKIM fail: do nothing, send to spam, block it completely. It also sends you reports so you can see who is sending email as you

From a security standpoint it gives you control to block fake emails.

From a deliverability standpoint it gives you a large improvement in emails being delivered to the right places (Google and Microsoft expect this now)

Simple way to think about all three together

SPF = Who is allowed to send

DKIM = Is the message real and unchanged

DMARC = What to do if something is wrong

If you have read this incredibly boring post and are still interested we can do a simple review for you. We also can fix it so that you can improve your security and deliverability.

Don't lose out on money because your emails are not getting delivered or scammers are sending as you. Reach out to me here on LinkedIn and we can help improve this.