When mail arrives for an address (or catch-all) routed to an endpoint, Inboundr POSTs a signed email.received event to the endpoint’s URL.

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Request headers

These headers were originally spelled X-Inbound-*. Every delivery currently carries both spellings with identical values, so existing handlers keep working. New handlers should read X-Inboundr-*; the older names will be withdrawn once no endpoint depends on them.
Any custom headers you configured on the endpoint are also included.

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Payload

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string
Always email.received.
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string
The stored email id (em_…). Use it with the emails API to fetch attachments or full context.
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string
Conversation id. Fetch the rest of the thread via GET /v1/threads/{id}.
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array
Attachment metadata only (filename, contentType, size). Download content via the attachments endpoint.
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object
spam, spf, and dkim authentication results.

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Responding

Return any 2xx status to acknowledge receipt. Anything else — including a 3xx redirect or a timeout — is treated as a failed attempt and retried.
Acknowledge fast. Do heavy processing asynchronously and return 200 immediately so you stay within the endpoint’s timeout (default 10s).