More than one DMARC record is published
`_dmarc.your domain` publishes more than one separate DMARC records.
Why it matters
`_dmarc.your domain` publishes more than one separate DMARC records. A receiver that finds more than one applies NONE of them (RFC 7489 §6.6.3), so the domain is in exactly the position it would be in with no DMARC record at all — forged mail claiming to come from you is delivered, and the policy you think is protecting you is not being read. This usually happens when a second record is added by a tool or a provider instead of the existing one being edited. Merge the two into a single TXT record at this name and delete the other.
How ShipReady detects it
Email-authentication DNS records (DMARC / SPF). Almost every AI-built SaaS sends transactional email — password resets, magic links, receipts — through Resend, SendGrid or Postmark. Setting that up gets the mail delivered; it does not stop anyone else sending mail that claims to come from the same domain. Without a DMARC policy, a receiving server has no instruction to reject a forgery, so an attacker can send "reset your password" from the product's own domain and the message will land in the inbox looking authentic. This check is almost entirely DNS rather than HTTP — one exception is MTA-STS, whose policy is only half-published in DNS; the other half is a file fetched over HTTPS (see _check_mta_sts). Nearly everything else here is the most deterministic kind of check the scanner has: a record either exists or it does not, so there is no heuristic and no false-positive surface. The one place judgement is required is deciding WHICH domain to ask about — see _organizational_domain.
Detection is deterministic. ShipReady reports this only when it observes the condition directly, and prefers to miss a real problem over inventing one. Rule version 1.10.0.
How to fix it
This is the prompt ShipReady puts in your report — written to be pasted straight into Cursor, Claude Code, or whichever assistant built the app.
The domain your domain publishes more than one DMARC record, and a receiver that finds more than one applies none of them (RFC 7489 §6.6.3) — so you currently have no DMARC protection at all despite the records being there. Open your DNS provider, list every TXT record at _dmarc.your domain, and merge them into ONE. Keep the strictest policy you intend to run and combine the reporting addresses into a single comma-separated rua= list, e.g. "v=DMARC1; p=quarantine; rua=mailto:you@your domain,mailto:reports@your-dmarc-tool.com". Delete the others. This usually happens when a monitoring tool adds its own record instead of editing yours, so check whether one of them is managed by a tool before you remove it. Afterwards, query the name again and confirm exactly one record comes back.
Frequently asked questions
- What does "More than one DMARC record is published" mean?
- `_dmarc.your domain` publishes more than one separate DMARC records.
- How serious is it?
- ShipReady rates this high. Fix before launch. A real weakness that an attacker can act on.
- How do I fix it?
- Paste the fix prompt on this page into Cursor, Claude Code or your AI editor. It is the same prompt ShipReady puts in your report.
- Can I check my own site?
- Yes — ShipReady scans up to ten pages of any public site for free and reports this alongside every other check. The free report lists every issue it finds and shows full evidence and a fix prompt for the critical and high-severity ones; medium and low findings are counted and unlock on Pro.
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