SparkPost is too flaky for critical emails

If SparkPost is flaky for critical emails, the safest move is to treat it as a non-primary provider and add resilience around delivery.

A practical approach:

1. Use a fallback provider

   • Keep SparkPost as one route, but add a backup like SendGrid, Mailgun, Amazon SES, or Postmark.
   • Route critical mail through the more reliable provider first, then fail over automatically if needed.

2. Queue outgoing emails

   • Don’t send synchronously from the app request path.
   • Put emails on a job queue with retries, exponential backoff, and dead-letter handling.

3. Implement provider failover

   • If SparkPost times out, returns 5xx, or has elevated error rates, switch traffic to backup provider.
   • Use health checks and circuit breaking rather than waiting for hard failures.

4. Monitor delivery outcomes

   • Track send success, bounce rate, latency, webhook events, and provider uptime.
   • Alert on spikes in transient failures or delayed sends.

5. Separate critical from non-critical

   • Password resets, receipts, and security notifications should use the most reliable path.
   • Marketing or low-priority mail can stay on the cheaper or less consistent provider.

6. Consider dedicated infrastructure if volume is high

   • For very important transactional email, AWS SES with proper setup, or Postmark, is often chosen for stability.

If you want, I can help you design a multi-provider email failover setup or recommend a provider based on your needs and budget.