I was one of the trailblazers who defeded from .ml and once the domain filtering feature was added, I added lemmy.ml to my domain blocks in the admin panel. Reason being, I don’t want .ml content including crossposts and re-posted images.

I thought that was working great until I noticed today that I hadn’t gotten any posts to !books@lemmy.world for several months. Even trying to manually resolve a post pulled from there directly, it wouldn’t load. Finally checked the server logs, and there was a Domain is blocked event right after the logged call to ResolveObject. Of course the logs didn’t say what domain.

Long story short, after scouring the randomly-selected test post to see if there was some kind of false positive, I finally realize there’s a “Related Community” link to a community on .ml in c/Books’s community description and that was what it was hitting on. Any post coming in to c/Books was being rejected because the community description linked to something in my site’s URL filters.