curl --location --request POST 'https://test-api.yunjishop.cn/recommend/app/letter/queryLetterList'
{
"code": 0,
"msg": "string",
"trace": "string",
"data": [
{
"sentLetterId": 0,
"fromUserId": 0,
"createTime": "2019-08-24T14:15:22Z",
"letterContent": "string"
}
]
}