Glossary

What is DMARC?

DMARC is a DNS record that tells receiving mail servers what to do when a message claiming to be from your domain fails SPF and DKIM, and where to send reports about it. Its policy can be none, quarantine or reject. Google and Yahoo ask bulk senders to publish at least a policy of none.

Published by Sellinger AI. Numbers and settings checked on 24 October 2026 against the fact register. Report an error.

How does DMARC work?

DMARC stands for Domain based Message Authentication, Reporting and Conformance. It checks alignment: whether the domain that passed SPF or DKIM matches the domain in the visible From address. If neither aligns, the message fails DMARC, and the receiver applies your policy.

DMARC policies
Policy	What the receiver is asked to do	When to use it
p=none	Deliver as normal, but send reports	First weeks, while you find every service that sends as you
p=quarantine	Treat failing mail as suspicious, often the spam folder	Once reports show your real mail passes
p=reject	Refuse failing mail	When you are confident no legitimate mail fails

What does a starter record look like?

An illustrative starter record, published as a TXT record at _dmarc.yourdomain.com: v=DMARC1; p=none; rua=mailto:dmarc-reports@yourdomain.com. The rua address receives daily summary reports. Read them for a few weeks before you tighten the policy.

What do Google and Yahoo require?

Google's email sender guidelines ask bulk senders, meaning senders of 5,000 or more messages a day, to publish a DMARC record; the policy can be none, and mail must pass SPF or DKIM with a domain that matches the From header. Yahoo Sender Hub asks for a policy of at least p=none and strongly recommends a rua reporting address. Both read on 19 October 2026 for Google and Yahoo bulk sender rules.

How Sellinger handles it

Sellinger sends from your own connected Gmail or Outlook mailbox. It does not set up or check your domain records, run inbox placement tests or monitor your domain, so you or your IT provider set up SPF, DKIM and DMARC at the domain. Publish DMARC on the sending domain before a campaign, and add a reporting address so you can see failures.

Common questions

Does DMARC p=none protect my domain?

Only partly. It gives you reports but asks receivers to deliver failing mail anyway. Move to quarantine or reject once your own mail passes.

What is DMARC alignment?

The match between the domain that passed SPF or DKIM and the domain in the From address. Relaxed alignment accepts subdomains.

Do small cold email senders need DMARC?

It is the safe choice. Providers cannot tell in advance that you are small, and a domain without DMARC looks less trustworthy.

Sources and method

Google email sender guidelines and Yahoo Sender Hub, read 19 October 2026 for the linked blog post. Sellinger behaviour from the fact register, checked 24 October 2026.