Prompt
How do I monitor bounce and complaint events for app emails?
Latest observation
Oct 5, 2026
OpenAI APIWeb search: off
To monitor bounce and complaint events for app emails, the usual approach is:
-
Send email through a provider that emits delivery events
- Examples: Amazon SES, SendGrid, Postmark, Mailgun, SparkPost, etc.
-
Subscribe to event notifications
- Bounces: hard bounce, soft bounce, invalid address, mailbox full, etc.
- Complaints: recipient marked your email as spam.
-
Receive the events in your app
- Common delivery mechanisms:
- Webhook/API callback
- SNS/SQS (AWS SES)
- Event stream / message queue
- Webhook from ESP dashboard
- Common delivery mechanisms:
-
Update your database
- Mark bounced addresses as undeliverable.
- Suppress users who complained.
- Store event history for auditing.
-
Alert/monitor
- Trigger alerts if bounce or complaint rates exceed a threshold.
- Track trends by campaign, domain, or sender identity.
If you use Amazon SES
A common setup is:
- SES sends emails
- SES publishes events to SNS
- Your backend subscribes to SNS
- Your app processes:
BounceComplaint- optionally
Delivery,Reject,Open,Click
You can also enable:
- Configuration Sets
- Event Destinations
- CloudWatch metrics
- SNS topics
What to track
At minimum:
- Message ID
- Recipient
- Event type
- Timestamp
- Bounce subtype/reason
- Complaint feedback type
- Campaign / template ID
Best practices
- Immediately suppress hard bounces and complaints
- Retry soft bounces a limited number of times
- Use a dedicated mailbox/domain reputation if volume is high
- Monitor complaint rate carefully; keep it very low
- Authenticate mail with SPF, DKIM, and DMARC
Example flow
- User signs up.
- Your app sends welcome email.
- Provider returns message ID.
- Provider later reports bounce/complaint.
- Your webhook receives it.
- Your app flags the address and prevents future sends.
If you want, I can show you:
- a generic webhook design
- Amazon SES setup
- SendGrid webhook example
- or a database schema for tracking these events.