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.