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Sending Domain Blocked

A sending domain can be blocked because of missing DNS records, policy violations, high bounce rates, high complaint rates, or reputation risk.

First checks​

  1. Confirm SPF, DKIM, and tracking-domain records still resolve.
  2. Check whether DNS changed recently.
  3. Review bounce and complaint trends.
  4. Check whether a new list, campaign, or integration increased volume.
  5. Confirm unsubscribe and suppression handling is working.

Escalation packet​

Prepare:

  • Sending domain.
  • Approximate time the block started.
  • Recent DNS changes.
  • Recent volume changes.
  • Bounce and complaint metrics.
  • Example transmissionId values.