public function getContext()
    {
        return array_filter(array(
            'subject' => $this->getSubject(),
            'from' => $this->addressToString((array) $this->getSender()),
            'to' => $this->addressToString((array) $this->getRecipients()),
            'cc' => $this->addressToString((array) $this->getCc()),
            'bcc' => $this->addressToString((array) $this->getBcc())
        ));
    }