I have a question for the IndieWeb community: What can we do against Webmention spam, except filter it out, when it fails validation? I receive hundreds of invalid Webmentions a day, and even using a filtering DNS server doesn’t seem to help much. But I also don’t want to waste network traffic to access all those spam sites. Is there any good block list I can check first before doing the request for validation? I thought about Akismet, but the API has no such option to only check the submitted URL.