How to analyze delivery logs?

Delivery logs contain detailed records of every send attempt. Effective analysis turns this data into actionable insights.

• Key data points in logs:
• Recipient address and domain
• Timestamp of attempt
• Status (delivered, bounced, deferred)
• SMTP response code and message
• Delivery time (how long it took)
• IP used for sending
• Analysis approaches:
• Filter by status: Isolate failures to focus troubleshooting
• Group by domain: Identify domains with problems (all Gmail bouncing? Microsoft deferring?)
• Group by error: Find common failure reasons (same error message across recipients)
• Time trends: Track when problems started, correlate with changes
• IP analysis: Check if specific IPs have issues
• Questions to answer:
• What percentage of messages delivered successfully?
• Which domains have the highest failure rates?
• What are the most common error messages?
• Did something change when problems started?
• Are problems getting better or worse over time?

ESP dashboards often provide aggregated views, but raw log access (via export or API) enables deeper analysis. Spreadsheets work for small data; larger volumes may need analytics tools or scripts.