Convert 8-bit MIME Parts to Base64

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Demonstrates the Chilkat Mime.Convert8Bit method, which recursively converts every part whose Content-Transfer-Encoding is 8bit or binary to base64. It takes no arguments and is a void method.

Note: The file paths are relative to the application's current working directory. Absolute paths may also be used. Supply the paths appropriate to your own environment.

Background: The original SMTP standard only guaranteed 7-bit transport, and some legacy servers still reject or mangle raw 8-bit and binary content. Converting those parts to base64 — a 7-bit-safe encoding — makes the whole message safe to relay through such systems without loss. It walks the entire tree, so a multipart message with several offending parts is fixed in one call.

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bool success = false;

Chilkat.Mime mime = new Chilkat.Mime();
success = mime.LoadMimeFile("qa_data/message.eml");
if (success == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

//  Recursively convert every part whose Content-Transfer-Encoding is 8bit or binary to base64.
//  This makes the MIME safe to transmit over channels that only support 7-bit text (such as some
//  legacy SMTP servers).
mime.Convert8Bit();

Debug.WriteLine("8bit/binary parts converted to base64.");
string mimeText = mime.GetMime();
if (mime.LastMethodSuccess == false) {
    Debug.WriteLine(mime.LastErrorText);
    return;
}

Debug.WriteLine(mimeText);