Why async verification is the default at high scale
If you need to validate millions of emails, synchronous request-response validation can become a bottleneck. It ties up app workers, increases tail latency, and makes failures harder to recover from. An async design separates user-facing traffic from verification throughput. You enqueue tasks, process them in workers, and store results as they arrive. EmailVerifierAPI.com fits this model because it supports high-throughput verification and predictable outcome categories that are easy to persist.
Reference architecture
- Producer: imports list rows and enqueues jobs.
- Queue: durable backlog (database queue, Redis, or managed queue).
- Workers: call EmailVerifierAPI.com and write results.
- Webhook receiver: optional, to receive completion events.
- Reporting: aggregates valid, invalid, risky, and unknown segments.
Key design requirements
Idempotency
Every job must be safe to retry. Use an idempotency key per email record (for example import_id + row_id). Store a “processed” marker and skip duplicates.
Retry policy
- Retry network errors with exponential backoff.
- Do not retry invalid outcomes.
- Cap retries to prevent infinite loops.
Batching strategy
Batching reduces overhead. Process N records per worker cycle, but keep batches small enough to avoid timeouts. Many teams start with 100 to 1,000 records per batch depending on response time and infrastructure.
Webhook handling (optional but powerful)
If you use webhooks for completion notifications, treat the receiver as a public endpoint that must be secured.
- Signature verification: validate that the callback is authentic.
- Replay protection: reject duplicate event IDs.
- Fast acknowledgement: enqueue downstream processing and respond quickly.
Data model for results
Store at least:
- Email (normalized), domain, and source metadata.
- Verification status (valid, invalid, risky, unknown).
- Reason codes and risk flags as provided by EmailVerifierAPI.com.
- Timestamps, latency, and attempt counts.
Operational reporting that drives revenue
- Valid count and percentage.
- Invalid count and percentage.
- Risky/unknown count with recommended handling rules.
- Top failing domains and acquisition sources to fix upstream.
How to deploy safely
- Run a pilot import and verify the outcome distribution matches expectations.
- Enable throttling and concurrency controls on workers.
- Monitor queue depth and processing rate, adjust worker count.
- Use EmailVerifierAPI.com result categories to segment sends and reduce bounce exposure.
Bottom line
Async verification is how you validate at scale without blocking your app. With EmailVerifierAPI.com, you can build a durable pipeline with idempotency, retries, and reporting that turns raw lists into deliverable segments that protect your sender reputation and improve campaign ROI.