function rss_post_thumbnail($content) {
global $post;
if(has_post_thumbnail($post->ID)) {
$content = ‘

‘ . get_the_post_thumbnail($post->ID) .
‘

‘ . get_the_excerpt();
}
return $content;
}
add_filter(‘the_excerpt_rss’, ‘rss_post_thumbnail’);
add_filter(‘the_content_feed’, ‘rss_post_thumbnail’);