How do blocklist-related bounces differ across ESPs?

Blocklist bounce presentation varies across ESPs:

Variation factors:

Classification depth: Some ESPs identify specific blocklist; others just say "blocked." Category labels: "Block bounce," "reputation," "policy," or "spam." Detail preservation: Full original message vs summary. Actionability: Some include remediation links.

Common ESP approaches:

Detailed: Shows exact blocklist name, lookup URL, original error. Summarized: Classifies as "blocked" with general guidance. Minimal: Generic "rejected" without blocklist specifics.

Impact on senders:

Detailed reporting enables faster troubleshooting. Summarized may require checking logs. Minimal forces manual investigation.

Best practice:

Access raw SMTP logs when possible. Use ESP reporting as first indicator. Verify with direct blocklist queries.

ESPs translate blocklist rejections differently. Know how your ESP presents this data for effective troubleshooting.