Add an alias delivering into an organization mailbox, on the mailbox's domain. Created on the mail server first, then recorded. A taken address (alias or mailbox) is 409, a reserved local part 422, a mail-server refusal 502. Honours Idempotency-Key. (scope: mailboxes:write)

curl -X POST "https://example.com/mail-aliases" \  -H "Content-Type: application/json" \  -d '{    "mailbox_id": "4d23d1af-2eef-4598-a5e0-1f19ae0b0c14",    "alias_local_part": "string"  }'

{  "data": {    "id": "497f6eca-6276-4993-bfeb-53cbbbba6f08",    "address": "user@example.com",    "mailbox_id": "4d23d1af-2eef-4598-a5e0-1f19ae0b0c14"  },  "error": null}