I get a empty email from "MAILER-DAEMON" somtimes.

Not all e-mails are like that.

Some emails reply to empty mail with "Re:Subject", but I don't know the cause.

I checked the SES log to determine the cause and found that the response code was 250.

The contents of the log are as follows.

{
    "notificationType": "Delivery",
    "mail": {
        "timestamp": "2022-04-01T01:54:58.846Z",
        "source": "sender@tenping.kr",
        "sourceArn": "arn:aws:ses:us-west-2:590989140517:identity/sender@tenping.kr",
        "sourceIp": "52.78.120.18",
        "sendingAccountId": "590989140517",
        "messageId": "0101017fe2d5389e-cd35215e-1af0-4364-97e1-6cb931ee3f8d-000000",
        "destination": [
            "help@ad-max.co.kr"
        ],
        "headersTruncated": false,
        "headers": [
            {
                "name": "Received",
                "value": "from WIN-IDAEGR3MKEU (ec2-52-78-120-18.ap-northeast-2.compute.amazonaws.com [52.78.120.18]) by email-smtp.amazonaws.com with SMTP (SimpleEmailService-d-NT1MBGB0G) id FrnU2dYrD6WaPMeqoEex for help@ad-max.co.kr; Fri, 01 Apr 2022 01:54:58 +0000 (UTC)"
            },
            {
                "name": "MIME-Version",
                "value": "1.0"
            },
            {
                "name": "From",
                "value": "텐핑 <sender@tenping.kr>"
            },
            {
                "name": "To",
                "value": "help@ad-max.co.kr"
            },
            {
                "name": "Date",
                "value": "1 Apr 2022 10:54:58 +0900"
            },
            {
                "name": "Subject",
                "value": "[텐핑] 소문 재시작 - K-유니콘기업 상장 전 미리 투자하는 \ufffd\ufffd\ufffd상장주식이 대세!"
            },
            {
                "name": "Content-Type",
                "value": "text/html; charset=utf-8"
            },
            {
                "name": "Content-Transfer-Encoding",
                "value": "base64"
            }
        ],
        "commonHeaders": {
            "from": [
                "\"텐핑\" <sender@tenping.kr>"
            ],
            "date": "1 Apr 2022 10:54:58 +0900",
            "to": [
                "help@ad-max.co.kr"
            ],
            "subject": "[텐핑] 소문 재시작 - K-유니콘기업 상장 전 미리 투자하는 \ufffd\ufffd\ufffd상장주식이 대세!"
        }
    },
    "delivery": {
        "timestamp": "2022-04-01T01:54:59.768Z",
        "processingTimeMillis": 922,
        "recipients": [
            "help@ad-max.co.kr"
        ],
        "smtpResponse": "250 2.0.0 OK  1648778099 r17-20020a170902be1100b00153fd4c3dcdsi813320pls.64 - gsmtp",
        "remoteMtaIp": "74.125.195.26",
        "reportingMTA": "a58-131.smtp-out.us-west-2.amazonses.com"
    }
}