If an email tool or a customer's mail server has told you that your domain has "no DMARC record found," it simply means your domain hasn't published a DMARC policy in its DNS zone yet. That's an easy gap to close, and doing so helps keep your outgoing mail out of spam folders and makes it much harder for scammers to send fake email that looks like it came from your domain.
What DMARC actually does
DMARC stands for Domain-based Message Authentication, Reporting, and Conformance. It's a DNS record that tells other mail servers what to do when a message claims to be from your domain but fails your existing SPF or DKIM checks. Without a DMARC record, receiving servers have no guidance at all, so a scammer can forge your domain in the "From" field and there's nothing technically stopping that message from looking legitimate.
DMARC also asks receiving servers to email you a daily summary of who is sending mail using your domain name, which passed authentication, and which didn't. That report is genuinely useful: it's often how businesses discover that a forgotten marketing tool or a spoofing attempt is sending mail under their name.
Why this matters more than it used to
Gmail, Yahoo, and Outlook/Microsoft 365 have all tightened their rules for accepting bulk email. If your domain sends any real volume of mail without a DMARC record in place, you risk having legitimate messages bounced outright rather than just filtered to spam. Even low-volume senders benefit from having the record in place, since it also improves how trustworthy your domain looks to spam filters generally.
How to publish a DMARC record
You'll need access to your domain's DNS zone. If your domain is registered or hosted through Avalon Hosting, this is managed from your Avalon hosting control panel; otherwise it's wherever your domain's nameservers are managed.
- Confirm the record is really missing. Use any DMARC lookup tool and search for
_dmarc.yourdomain.com. If nothing comes back, you're starting from scratch. - Decide on a starting policy. Always start in monitor-only mode rather than jumping straight to blocking mail — you want to see who is sending on your behalf before you risk cutting off legitimate email.
- Add a new TXT record in your DNS zone with the host name
_dmarc(this becomes_dmarc.yourdomain.com). A monitor-only record looks roughly like this, with your own domain in the reporting address:v=DMARC1; p=none; rua=mailto:[email protected] - Save the record and wait for it to propagate. DNS changes are often visible within an hour or two, though it can occasionally take up to a day or so to reach every resolver worldwide.
- Review your reports after a few weeks. Once you can see that all your legitimate senders (your website's contact form, your email marketing platform, your helpdesk, etc.) are passing authentication, you can tighten the policy to quarantine failing mail, and eventually to reject it outright.
Common issues
- Record ignored entirely: usually a small syntax mistake, such as a missing semicolon or an extra space. Copy the record carefully and validate it with a lookup tool.
- Legitimate mail suddenly failing: this almost always means a sending tool (like a CRM or invoicing platform) isn't yet included in your SPF record or isn't signing with DKIM. Add it before tightening your DMARC policy further.
- Moved to "reject" too soon: jumping straight to blocking mail before reviewing reports is the most common mistake. Give yourself a few weeks in monitor mode first.
Once your DMARC record is live and tuned correctly, it becomes one of the simplest, most effective defenses against someone impersonating your domain in a phishing attempt.
