gistfile1.js

function decodeBody(content, encoding) {                                                                                                      
    switch (encoding.toLocaleLowerCase()) {
        case "base64":
            content = content.replace(/\r/g, '');
            return new Buffer(content, 'base64').toString('utf8');

        case "quoted-printable":
        case "7bit":
        case "8bit":
            content = content.replace(/\r/g, '');
            return unquotedPrintable(content);

        default:
            console.warn("Unknown encoding: " + encoding);
            return content;
    }   
}

function unquotedPrintable(content) {
    return content
        .replace(/=\n/g, '') 
        .replace(/=([\da-f]{2})/ig, function(_, m) {
            return String.fromCharCode(parseInt(m, 16));
        }); 
}