Email infrastructure guide

Inbound Email Webhooks: Design Patterns and Safety

Use webhooks to process inbound messages without building a polling mailbox workflow.

An inbound-email webhook delivers a structured event to your application when a message arrives. The design challenge is safe parsing, authentication, idempotency, and handling retries without losing messages.

What this means in practice

  • Signed or authenticated webhook delivery
  • Message IDs for idempotent processing
  • Raw-message retention for recovery
  • Async handling for attachments and downstream work

Implementation checklist

  1. Validate the webhook source before parsing content.
  2. Persist the provider message ID before side effects.
  3. Queue long-running attachment or AI processing.
  4. Return a success response quickly and retry safely on transient failures.

Questions teams ask

Should I process attachments inside the webhook request?

Usually no. Persist the message and enqueue attachment work so acknowledgement remains fast and retry-safe.

How do I handle duplicate webhooks?

Treat the provider message ID as unique and make downstream operations idempotent.

Continue learning

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