PublicDNS Tools

DMARC Generator

Generate a DMARC TXT record for your domain and publish it under _dmarc.<domain>.

How to publish

  1. Generate the record using the tool.
  2. Create a DNS TXT record for: _dmarc.<your-domain>
  3. Paste the generated TXT value.
  4. Wait for DNS propagation, then re-run the DMARC check.

Generator fields

  • Policy (p): none (monitor), quarantine, or reject
  • rua: aggregate report mailbox (recommended). You can provide one or multiple emails.
  • aspf / adkim: alignment mode (r=relaxed, s=strict)
  • pct: percent of messages the policy applies to (0–100)

Recommended rollout

  1. Start: p=none + rua reporting
  2. Then: p=quarantine (optionally pct=25 → 50 → 100)
  3. Finally: p=reject once you are confident

Example

Host: _dmarc.example.com
TXT:  v=DMARC1; p=none; rua=mailto:dmarc-reports@example.com; aspf=r; adkim=r;

Notes

  • Use a dedicated mailbox for reports (they can be large).
  • If you use a reporting address on a different domain, you may need additional authorization records.
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