How to detect delivery bottlenecks using bounce data?

Bounce data reveals delivery bottlenecks:

Bottleneck indicators:

High deferral rates to specific domains. Clustering of 4xx codes during peak times. Rate limiting messages (421, RP-001). Connection timeout increases.

Analysis approach:

Track deferrals by hour and provider. Correlate with sending volume. Identify threshold where deferrals spike. Map to provider rate limits.

Bottleneck types:

Sending capacity: Your infrastructure limited. Receiving throttling: Provider limiting acceptance. Reputation-based: Limits due to reputation issues. Network: Connectivity or routing problems.

Resolution strategies:

Spread sends over longer periods. Improve reputation for higher limits. Add sending capacity. Optimize queue management.

Bottlenecks show where the flow is restricted. Bounce patterns map the constraints.