Quick Takeaways

• Google now adds a <reason> tag with a fixed Sender requirement failed string and the SMTP error code.
• The new detail lets you pinpoint SPF, DKIM, alignment or DNS‑related failures directly from the DMARC aggregate report.
• Common error codes include 421‑4.7.27 (SPF rate‑limit), 421‑4.7.30 (DKIM failure), 550‑5.7.25 (PTR/DNS mismatch) and 550‑5.7.1 (generic block).
• Palisade captures these signals in real‑time and surfaces them in a dedicated Sender Requirements Failure Report.
• Use the report to remediate authentication gaps, align your DNS records, and move toward full DMARC enforcement.

Background

Google has rolled out a helpful update to its DMARC aggregate reports: new diagnostic details about why an email fails sender authentication requirements. This approach helps senders of all sizes understand how they’re doing with respect to Google’s sender requirements in one place (their DMARC report) instead of needing to evaluate compliance from service to service and SMTP log to SMTP log.

The change originated from an industry discussion where Palisade’s CTO suggested making sender‑requirement failure reasons visible across the entire sending infrastructure via DMARC reports. Today the feature is live, giving organizations clearer visibility into authentication problems that were previously hard to pinpoint.

What the new XML looks like

Google’s DMARC XML feedback now includes additional information under the <policy_evaluated> section, especially the <reason> tag with a newly‑populated comment field:

<policy_evaluated>
  <disposition>none</disposition>
  <dkim>fail</dkim>
  <spf>fail</spf>
  <reason>
    <type>local_policy</type>
    <comment>Sender requirement failed: 550-5.7.1</comment>
  </reason>
</policy_evaluated>

The fixed prefix “Sender requirement failed:” is followed by the SMTP error code, which gives you a precise clue about the underlying issue.

Decoding the most common error codes

• 421‑4.7.27: Rate limiting due to SPF failure.
• 421‑4.7.29: Rate limiting because TLS was not used.
• 421‑4.7.30: Rate limiting because DKIM authentication didn’t pass.
• 421‑4.7.32: Rate limiting due to lack of alignment.
• 550‑5.7.25: Blocked because of missing or mismatched PTR (reverse DNS) record.
• 550‑5.7.27: Blocked due to SPF failure.
• 550‑5.7.30: Blocked because DKIM authentication failed.
• 550‑5.7.1: Blocked for other reasons such as spam reputation or RFC‑5322 non‑compliance.

These codes map directly to the SMTP rejection and deferral codes documented by Google (SMTP rejection codes), letting you quickly identify whether the failure is SPF, DKIM, alignment, DNS, or a deeper deliverability problem.

How Palisade helps you act on the data

Palisade has already integrated the new Sender Requirements Failure Report into our platform. The report surfaces the exact error code and associated message for every failing source, so you can:

• Pinpoint mis‑configured SPF or DKIM records.
• Detect missing PTR or forward/reverse DNS records.
• Identify alignment gaps that break DMARC enforcement.
• Prioritize remediation based on volume and impact.

All Palisade users can now view this report in the dashboard and set up alerts for specific failure types.

Next steps

If you’re still struggling to meet Google’s email sender guidelines, schedule a demo of Palisade Enforce to accelerate compliance and DMARC enforcement.

👉 Check your email security score

Related reading

For a deeper dive into specific error codes, see Palisade’s guide on Yahoo and Gmail error codes.

FAQs

1. What is the Sender requirement failed tag in Google DMARC reports? It is a new <reason> element that includes a fixed prefix and the SMTP error code, giving precise insight into why authentication failed.
2. How can I differentiate between SPF and DKIM failures in the report? Look at the spf and dkim fields inside <policy_evaluated> and match them with the accompanying SMTP error code (e.g., 550‑5.7.27 indicates SPF failure).
3. Do these new details affect existing DMARC reporting tools? Modern tools that parse the XML can extract the <reason> tag. Palisade’s platform already does this, and other vendors may update their parsers.
4. Can I use the new information to improve my email deliverability? Yes – by fixing the specific authentication or DNS issues highlighted, you reduce rejections and improve inbox placement.
5. Is there a way to get alerts when a particular error code spikes? Palisade lets you create custom alerts on the Sender Requirements Failure Report, so you’re notified of spikes in any code such as 421‑4.7.27 or 550‑5.7.25.