# List the addresses a mailbox may send as

Returns the addresses this mailbox may use as From, primary first: its routed addresses on domains that may send, then `*@domain` wherever a catch-all on a sending domain lands in it (RFC 8621 §6's wildcard, any address on that domain). The same list JMAP Identity/get reports. `subaddressing` says whether an address's `+tag` forms are sendable too. A domain-scoped key sees only its own domains. Suggestions for a From picker, not an authorization list: an address a narrower catch-all pattern routes here is sendable without being listed, and the list stops at 100 addresses, so submission decides.

## `GET /api/v1/mailboxes/{mailboxId}/send-as`

### Path parameters

- `mailboxId` (string, required) — Mailbox ULID identifier

### Responses

**200** — The addresses, primary first

`application/json` → SendAsAddresses

- `addresses` (object[], required) — Primary address first, then the mailbox's other routed addresses on domains that may send, then wildcards; at most 100 addresses. Not exhaustive: an address a narrower catch-all pattern routes here is sendable without being listed
  - `email` (string, required) — A lowercased address this mailbox may send as, or `*@domain` where a catch-all lets it send as any address on that domain (RFC 8621 §6's wildcard)
  - `subaddressing` (boolean, required) — Whether `local+tag@domain` forms of this address are sendable too. Always false on a wildcard, which already covers every local part

**401** — unauthorized: the bearer credential is missing, malformed, expired, or revoked. Carries a `WWW-Authenticate: Bearer` challenge

`application/json` → ErrorBody

**404** — Mailbox not found or not accessible to this principal

`application/json` → ErrorBody

**503** — temporary_failure: the platform's storage could not answer just now; retry after the Retry-After window. Any operation can answer this. A write that got it may have been applied, so retry it with the same idempotency key where it takes one, or read the state back first (see Transient failures in the API description)

`application/json` → ErrorBody

### Example request

```bash
curl -X GET 'https://api.open.email/api/v1/mailboxes/{mailboxId}/send-as' \
  -H 'Authorization: Bearer oek_…'
```