public function generatePlainPartFromBody()
    {
        $plainPart = $this->findPlainPart();
        if ($plainPart) {
            $this->getSwiftMessage()->detach($plainPart);
        }
        unset($plainPart);

        $this->getSwiftMessage()->addPart(
            Convert::xml2raw($this->getBody()),
            'text/plain',
            'utf-8'
        );

        return $this;
    }