Guides
Each of these starts from a problem you might be having and ends with a record you can publish. No prior knowledge of email authentication assumed.
- SPF: too many DNS lookups
SPF allows ten DNS lookups. Go over and receivers ignore your record entirely. How to count them, and the three ways to get back under.
- What DMARC p=none actually does
p=none collects reports and blocks nothing. It is the right place to start and the wrong place to stop. How to get to enforcement without losing mail.
- Your DMARC reports may be going nowhere
A DMARC record can look flawless and still deliver you no reports at all. Two failure modes that leave you blind, and how to check for both.
- Google and Yahoo's sender requirements
What Google and Yahoo have required from senders since February 2024, who it applies to, and how to tell whether you comply.
- Finding your DKIM selector
DKIM selectors cannot be listed from DNS. Why every checker is guessing, how to find yours for certain, and the trap that makes some tools report keys that do not exist.