Email authentication

Free Email Authentication Checker

Run SPF, DKIM and DMARC checks on your domain in one place — and fix the three records that decide whether your emails land.

What is email authentication?

Email authentication rests on three DNS records — SPF, DKIM and DMARC. Together they prove to Gmail, Outlook and every other provider that your mail is legitimate. Miss one and your deliverability suffers; get all three green and you’ve built the foundation for inbox placement.

SPF, DKIM and DMARC in plain terms

  • SPF lists which servers may send for your domain.
  • DKIM signs each message so receivers can verify it.
  • DMARC ties the two together and tells receivers what to do on failure.

How to use this checker

  1. Enter your domain — the tool runs all three checks at once.
  2. Review each result and note what’s missing or misconfigured.
  3. Fix the relevant TXT records in your DNS, then re-run until everything passes.

Why it matters for outreach

Before you scale any email channel, these three records have to be clean. Broken authentication is the silent reason good campaigns underperform — messages never reach the inbox. Get the foundation right, then run structured multichannel outreach on top of it.

FAQ

What’s the difference between SPF, DKIM and DMARC?

SPF authorizes sending servers, DKIM cryptographically signs messages, and DMARC sets the policy for what happens when SPF or DKIM fails. You need all three.

Which one matters most?

All three work together. SPF and DKIM prove legitimacy; DMARC makes them enforceable and gives you reporting. A gap in any one hurts deliverability.

How often should I check them?

Check after any DNS or email-provider change, and review periodically — records drift as you add tools and senders over time.

Do these affect cold email deliverability?

Directly. Mailbox providers weigh authentication heavily. Clean SPF, DKIM and DMARC are the baseline for landing outreach in the inbox.

Related tools

SPF Checker DKIM Checker DMARC Checker