A valid request URL is required to generate request examples{
"error": {
"code": "invalid_signature",
"message": "signature verification failed"
}
}{
"error": {
"code": "forbidden",
"message": "your role does not allow this action"
}
}{
"error": {
"code": "inbound_mail_unavailable",
"message": "inbound email is not available on this server"
}
}Receive an inbound support email
Where the mail provider delivers everything addressed to the inbound mail domain. You do not call this — the URL is configured once, in the mail provider’s own dashboard, and the provider calls it every time somebody writes to a support address.
It is outside /v1 on purpose, the provider-webhook rule: the version prefix is a promise about endpoints you call from your own code, and this URL lives in a setting inside somebody else’s dashboard.
The signature is the only credential. Each delivery is signed (svix scheme), and a request that does not verify is refused with nothing stored. There is no mode in which an unverifiable body is accepted.
Where a mail lands is resolved from the mail itself, most specific claim first: a reply+…@ recipient names one conversation (the address advertised in that conversation’s own outbound replies); failing that, In-Reply-To/References are matched against the stored thread within the environment a publishable-key recipient names; failing that, a new email conversation is opened and its contact resolved by the sender’s address. A verified mail that names no conversation and no environment is acknowledged with 200 and dropped — a redelivery cannot fix an address.
Retries are safe. Every stored message is recorded under the email’s own Message-ID for its environment, so a redelivery takes effect exactly once and answers 200 like the first delivery did.
A valid request URL is required to generate request examples{
"error": {
"code": "invalid_signature",
"message": "signature verification failed"
}
}{
"error": {
"code": "forbidden",
"message": "your role does not allow this action"
}
}{
"error": {
"code": "inbound_mail_unavailable",
"message": "inbound email is not available on this server"
}
}Body
The provider's email.received event, exactly as it was signed. The full payload is kept with the stored message, so nothing the threading heuristics skip is lost.
A Resend inbound email event. Its shape is the provider's, not ours.
Response
Delivered. The message joined its conversation — or was already there (a redelivery), was addressed to nobody this server knows, or was an event type this endpoint does not consume; all of those acknowledge rather than invite a retry.