designate/api-ref/source/samples/recordsets/create-mx-recordset-request.json

{
    "name" : "mail.example.org.",
    "description" : "An MX recordset.",
    "type" : "MX",
    "ttl" : 3600,
    "records" : [
        "10 mail1.example.org.",
        "20 mail2.example.org.",
        "30 mail3.example.org.",
        "40 mail4.example.org."
    ]
}