Email authentication guides
Practical, no-nonsense guides to SPF, DKIM and DMARC. Fix what is broken and keep your mail out of spam.
How to Stop Someone From Spoofing Your Email Domain
A step-by-step playbook to stop attackers from sending email as your domain: audit every legitimate sending source, get SPF and DKIM passing and aligned, then move DMARC to a reject policy. Includes what this stops, what it does not (lookalike domains and display-name spoofing), and a free lookup to check your current status.
How to Set Up BIMI and Get a VMC So Your Logo Shows in Gmail
BIMI puts your brand logo next to your emails in Gmail, Apple Mail and Yahoo, but only after DMARC is at enforcement and, for Gmail, only with a verified mark certificate. This guide covers the full pipeline: the DMARC prerequisite, prepping an SVG Tiny P/S logo, choosing a VMC versus the cheaper CMC, publishing the v/l/a record, and a troubleshooting checklist for when the logo still will not show.
SPF, DKIM and DMARC Explained
The three records that decide whether your email is trusted or spoofed. What each one does, how they work together, and how to check yours.
How to Set Up an SPF Record
SPF lists which servers may send mail as your domain. Here is how to build the record correctly, end it with a strong policy, and stay under the lookup limit.
How to Set Up DKIM
DKIM signs your mail so receivers can prove it came from you. Here is how to generate the key, publish the record, enable signing, and confirm it works.
How to Set Up DMARC
DMARC turns SPF and DKIM into a real defense and shows you who sends as your domain. Here is how to set it up from scratch and advance it safely.
How to Fix a Missing DMARC Record
No DMARC record found means your domain has no spoofing policy and no visibility. Here is why it happens and the exact record to publish.
DMARC Policy: Moving from p=none to Reject Safely
p=reject is the only DMARC policy that stops spoofing. Here is how to get there in stages without blocking your own legitimate mail.
How to Fix DKIM Alignment Failures
DKIM can pass while DMARC still fails. The reason is alignment. Here is what alignment means and how to make your signature match your From domain.
Why Your Emails Go to Spam
When mail lands in spam, the first suspect is authentication, not content. Here are the SPF, DKIM and DMARC reasons and how to fix each one.
Google and Yahoo Sender Requirements
Since 2024, Google and Yahoo require senders to authenticate their mail. Here is what the rules actually ask for and how to comply.
SPF, DKIM and DMARC for Microsoft 365
Microsoft 365 sends your mail but does not authenticate your domain for you. Here are the exact SPF, DKIM and DMARC records to publish.