Custom webhook events
Updated Apr 8, 2026 · 4 min read
Subscribe any tool to Inboxlee mailbox lifecycle events.
On this page · 4
- Available events
- Configuring
- Verifying signatures
- Retry policy
Inboxlee POSTs JSON payloads to a URL you configure when mailbox-lifecycle events happen. Use this to wire any tool - Slack, PagerDuty, your billing system, an internal CRM.
Available events
Configuring
In Inboxlee → Settings → Webhooks → Create. Provide a URL, select events, choose a signing secret. Inboxlee signs every payload with HMAC-SHA256.
Verifying signatures
X-Inboxlee-Signature: sha256=<hmac-hex> X-Inboxlee-Timestamp: <unix-seconds>
Reject any payload where the timestamp is more than 5 minutes old, or the signature does not match HMAC-SHA256(secret, timestamp + "." + body).
Retry policy
On 4xx/5xx response, Inboxlee retries with exponential backoff up to 24 hours, then drops the event. The dashboard surfaces failed deliveries so you can investigate.