Email authentication guides
Practical, no-nonsense guides to SPF, DKIM and DMARC. Fix what is broken and keep your mail out of spam.
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.
How to Fix the SPF Too Many DNS Lookups Error
SPF fails with a permerror once your record needs more than ten DNS lookups. Here is why it happens and three reliable ways to get back under the limit.