How do I keep track of failed email sends?

To keep track of failed email sends, use a combination of logging, retries, and alerting. The best approach depends on whether you’re sending emails from an app, a marketing tool, or a server.

1. Log every send attempt

Store details for each email attempt:

• Recipient
• Subject/message ID
• Timestamp
• Status: queued, sent, failed, bounced
• Error message / provider response
• Retry count

This gives you an audit trail and makes failures easy to inspect later.

2. Capture provider webhooks

If you use a service like SendGrid, SES, Mailgun, or Postmark, enable their event webhooks for:

• Delivery
• Bounce
• Complaint
• Deferred
• Drop/failure

These are more reliable than only checking your app’s immediate send response.

3. Retry transient failures

Some failures are temporary:

• Timeout
• Rate limit
• Mail server unavailable

Use a retry policy with:

• Exponential backoff
• Max retry limit
• Dead-letter queue or failure bucket after retries are exhausted

4. Separate permanent vs temporary failures

Classify errors:

• Permanent: invalid address, blocked recipient, spam rejection
• Temporary: network error, mailbox full, graylisting

Permanent failures should usually stop retrying and be marked clearly.

5. Add alerts and dashboards

Set up monitoring for:

• Failure rate spikes
• Bounce rate spikes
• Queue backlog
• Repeated provider errors

Send alerts via Slack, email, or PagerDuty when thresholds are exceeded.

6. Keep a failure store

Common options:

• Database table for failed sends
• Log aggregation system (ELK, Datadog, CloudWatch)
• Queue/DLQ for messages that couldn’t be delivered

A simple database table might include:

• id
• recipient
• subject
• status
• error_code
• error_details
• attempts
• last_attempt_at
• created_at

7. Make failures visible to users or admins

If relevant, show a “failed” state in the UI so support or users can see which emails didn’t send and why.

If you want, I can also show you:

• a database schema for tracking failed emails,
• sample code for a specific language,
• or a recommended retry workflow.