Graph API 响应类似于以下内容，并Authentication-Results为我提供了相关的源发件人 IP -

{
    "@odata.context":"<some-value>",
    "@odata.etag":"<some-value>",
    "id":"<some-value>",
    "internetMessageHeaders":[
        {
            "name":"MIME-Version",
            "value":"1.0"
        },
        {
            "name":"Content-Type",
            "value":"multipart/report"
        },
        {
            "name":"x-custom-header-group-name",
            "value":"Washington"
        },
        {
            "name":"x-custom-header-group-id",
            "value":"WA001"
        },
        {
            "name":"Receiver",
            "value":"<some-ip>"
        },
        {
            "name":"Receiver",
            "value":"<some-ip>"
        },
        {
            "name":"Authentication-Results",
            "value":"spf=pass (sender ip is <some-ip>)...,"       
        }
    ]
}

现在，你只需要一个正则表达式来提取 -

1. 获取存在于 Authentication-Results
2. 使用正则表达式 -\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}提取 IP，使用与正则表达式匹配的第一次出现。