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What causes blocklist listings (technical vs behavioral)?

Technical causes:

  • Compromised server or account sending spam
  • Open relay being exploited
  • Malware infection
  • Poor network hygiene

Behavioral causes:

  • Sending to purchased or scraped lists
  • High complaint rates
  • Spam trap hits
  • Ignoring unsubscribes
  • Deceptive content or practices

Hybrid causes:

  • Compromised forms adding bad addresses
  • Poor list hygiene allowing trap accumulation
  • Volume spikes from automation errors

Investigation: Determine which category caused your listing to implement appropriate fixes.

Was the ship hijacked (technical) or carrying illegal cargo (behavioral)?

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