Set name for attachment

[alexh-swdev]

(How) can I set the (file)name for an attachment?
I am adding the file this way:

foreach(QString file, files) {
    auto fi = QFileInfo(file);
    auto fName = fi.fileName();
    auto document = std::make_shared<SimpleMail::MimeAttachment>(std::make_shared<QFile>(file));
    document->setContentName(fName.toUtf8());
    message.addPart(document);
}

The filename is not displayed properly in the email (it is not "human readable"). When I look at the sourcecode, the relevant part looks like

--9cf173c69cdd4e0c8e2d9216259c5b75
Content-Type: text/csv; name="?UTF-8?B?SW52ZW50b3J5TG9nLmNzdg==?="
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="=?UTF-8?B?SW52ZW50b3J5TG9nLmNzdg==?="

Am I doing this wrong or is this a bug? The filecontent of the attachment "arrives" correct