List messages
Returns a paginated list of messages received in the specified inbox, ordered newest first.
**Path parameters:**
- `:inbox` — URL-encoded inbox address (e.g., `test%40domain.com`)
**Query parameters:**
- `limit` *(optional)* — Number of messages to return per page. Default: `20`. Max: `100`.
- `before` *(optional)* — Cursor for pagination. Pass the `id` of the last message from the previous page to fetch the next page.
**Response fields (per message):**
- `id` — Unique message identifier
- `from` — Sender address
- `subject` — Email subject line
- `receivedAt` — ISO 8601 timestamp
- `otp` — `"__DETECTED__"` if an OTP was found but plan is below Growth; full value on Growth+
**Behaviour:**
- Returns an empty array `[]` if no messages have been received.
- Use the `before` cursor with the last `id` in the response to paginate through older messages.
**Plan:** All plans (Free and above). Full OTP value in listing requires Growth plan or higher.