When I attached simple jpeg file, the mail received has corrupted one like below, same for xlsx file, it can not be open due corrupted.

url de l'image)

part = curl_mime_addpart(alt);
curl_mime_data(part, msg.toStdString().c_str(), CURL_ZERO_TERMINATED);
curl_mime_type(part, "text/html; charset=utf-8 ");

/* Create the inline part. */
part = curl_mime_addpart(mime);
curl_mime_subparts(part, alt);
curl_mime_type(part, "multipart/alternative");
slist = curl_slist_append(nullptr, "Content-Disposition: inline");
curl_mime_headers(part, slist, 1);

/* Add the current source program as an embbeded image. */
part = curl_mime_addpart(mime);
QString logo=QApplication::applicationDirPath()+"/Images/logo.jpeg";
curl_mime_filedata(part, logo.toStdString().c_str());

// Add the current source program as an attachment.
part = curl_mime_addpart(mime);
curl_mime_filedata(part, quotefile.toStdString().c_str());

// Add the current source program as an attachment.
/*part = curl_mime_addpart(mime);
for(int i=0;i<fileList.count();i++)
{
    QString filename="./"+fileList[i];
    if(fileList[i]!="")
        curl_mime_filedata(part, filename.toStdString().c_str());
}*/
curl_easy_setopt(curl, CURLOPT_MIMEPOST, mime);

/* Send the message */
res = curl_easy_perform(curl);

libcurl version 7.85
operating system Qt 5.15.2 / Windows 10 / VS 2019

Any body can help me?

Best regards

Philippe