Renderer/RssRenderer.php
private function getAuthor(ItemInterface $item)
    {
        $authorData = $item->getFeedAuthor();
        $author = '';
        if(isset($authorData['name'])) {
            $author .= $authorData['name'];
        }
        if (isset($authorData['email'])) {
            $author .= empty($author) ? $authorData['email'] : ' ' . $authorData['email'];
        }

        if(!empty($author)) {
            return $author;
        }

        return null;
    }
private function getAuthor(ItemInterface $item)
    {
        $authorData = $item->getFeedAuthor();
        $author = '';
        if(isset($authorData['name'])) {
            $author .= $authorData['name'];
        }
        if (isset($authorData['email'])) {
            $author .= empty($author) ? $authorData['email'] : ' ' . $authorData['email'];
        }

        if(!empty($author)) {
            return $author;
        }

        return null;
    }
Extract the author email

@param \Nekland\Bundle\FeedBundle\Item\ExtendedItemInterface $item
@return string|null