我正在雷鸟中使用本地消息传递编写一个插件（following the ping pong example in python）调用Delphi程序将电子邮件本地复制为". eml"文件，我面临的问题似乎是编码，此外，生成的文件包含双引号（""）以及转义双引号（"）。我只想有一个1对1的副本，不想改变它的内容。
邮件内容示例：

"test"
€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“”•–—˜™š›œžŸ
éöàäèüâêû

但是，在文件中，它看起来更像这样：

\"test\"
€‚ƒ„…†‡ˆ‰Š‹ŒŽ‘’“â€â€¢â€“—˜™š›œžŸ
éöà äèüâêû

我可能已经发现了问题，解释如下：
https://www.i18nqa.com/debug/utf8-debug.html
然而，我真的不知道如何修改我的代码来解决这个问题。
谢谢你的帮助!
下面是我的背景. js：

async function main() {
        messenger.menus.create({
            contexts : ["message_list"],
            id: "copy@mail.lu",
            onclick : passMsg,
            title: messenger.i18n.getMessage("lang.menuTitle")
        });
    }
    
    async function passMsg(OnClickData) {
        if (OnClickData.selectedMessages && OnClickData.selectedMessages.messages.length > 0) {
            let MessageHeader = OnClickData.selectedMessages.messages[0];
            let raw = await messenger.messages.getRaw(MessageHeader.id);
            let port=browser.runtime.connectNative("copymail");
    
            port.onMessage.addListener((message) => {
              port.disconnect();
            });
    
            port.postMessage(raw);
        } else {
            console.log("No message selected");
        }
    }
    main();

下面是我的Delphi代码：

procedure WriteSTDInputToFile(const Filename: String);
    var
       Buffer:    array [0 .. 3] of Byte;
       msgLen:    LongInt;
       msg:       UTF8String;
       myFile:    TextFile;
       StdIn:     THandleStream;
       jsonValue: TJSONValue;
    begin
       StdIn  := THandleStream.Create(GetStdHandle(STD_INPUT_HANDLE));
    
       try
          msgLen    := 0;
          if StdIn.Read(Buffer, SizeOf(msgLen)) > 0 then
             msgLen := PLongInt(@Buffer)^;
    
          if msgLen > 0 then
          begin
             SetLength(msg, msgLen);
             StdIn.Read(PUTF8Char(msg)^, msgLen);
    
             if msg <> '' then
             begin
                AssignFile(myFile, Filename, CP_UTF8);
                ReWrite(myFile);
    
                jsonValue := TJSONObject.ParseJSONValue(msg);
    
                try
                   write(myFile, UTF8Encode(jsonValue.ToString));
                finally
                   jsonValue.Free;
                end;
    
                CloseFile(myFile);
    
             end;
          end;
    
       finally
          if Assigned(StdIn) then
             StdIn.Free;
       end;
    
    end;

生成的文件内容：

"X-MDAV-Result: clean
X-MDAV-Processed: mail.test.lu, Wed, 28 Oct 2020 08:13:22 +0100
X-Spam-Processed: mail.test.lu, Wed, 28 Oct 2020 08:13:22 +0100
Return-path: <copy@mail.lu>
X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on MAIL01E
X-Spam-Level: 
X-Spam-Status: No, score=0.7 required=10.0 tests=HTML_MESSAGE,MPART_ALT_DIFF
    shortcircuit=no autolearn=disabled version=3.4.2
Authentication-Results: test.lu;
    auth=pass (plain) smtp.auth=ascholtes@test.lu
Received: from [172.16.17.35] [(172.16.17.35)] by test.lu (172.31.3.6) with ESMTPSA id md50033234892.msg; 
    Wed, 28 Oct 2020 08:13:21 +0100
X-MDRemoteIP: 172.16.17.35
X-MDArrival-Date: Wed, 28 Oct 2020 08:13:21 +0100
X-Authenticated-Sender: ascholtes@test.lu
X-Rcpt-To: copy@mail.lu
X-MDRcpt-To: copy@mail.lu
X-Return-Path: copy@mail.lu
X-Envelope-From: copy@mail.lu
X-MDaemon-Deliver-To: ascholtes@test.lu
To: Ayuth Scholtes <copy@mail.lu>
From: Ayuth Scholtes <copy@mail.lu>
Subject: Test
Organization: CISS
Message-ID: <7eb36f7c-a7af-c272-c189-eded642c3e1c@test.lu>
Date: Wed, 28 Oct 2020 08:13:21 +0100
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:68.0) Gecko/20100101
 Thunderbird/68.10.0
MIME-Version: 1.0
Content-Type: multipart/alternative;
 boundary=\"------------6068A746223BB2C9F1771938\"
Content-Language: lb-LU

This is a multi-part message in MIME format.
--------------6068A746223BB2C9F1771938
Content-Type: text/plain; charset=utf-8; format=flowed
Content-Transfer-Encoding: 8bit

|\"test\" â¬âÆââ¦â â¡Ëâ°Å â¹ÅŽâââââ¢ââËâ¢Å¡âºÅžŸ éöàäèüâêû|

--------------6068A746223BB2C9F1771938
Content-Type: text/html; charset=utf-8
Content-Transfer-Encoding: 8bit

<html>
  <head>

    <meta http-equiv=\"content-type\" content=\"text/html; charset=UTF-8\">
  </head>
  <body>
    <pre class=\"lang-pascal s-code-block hljs delphi\"><code>\"test\"
â¬âÆââ¦â â¡Ëâ°Å â¹ÅŽâââââ¢ââËâ¢Å¡âºÅžŸ
éöàäèüâêû</code></pre>
  </body>
</html>

--------------6068A746223BB2C9F1771938--
"