This is a basic example of an easy-2-use email adress web crawler in PHP. With V1.02 this script now requires cURL to be installed on your host system or otherwise it won't be able to run. You have to run this script in the php command line.
$ php crawl.php https://www.robinsonliste.de/impressum 2
Visit https://cowthink.org/projects/crawl-php-email-crawler/ for some additional details.