I'd really rather not become a character in this story
Good luck. In my experience you can't speak up about stuff like this without putting yourself out there to some degree. Stay strong.
Regarding the email bounceback, could you perhaps try sending an email from another address (with a different host) to the same destination to confirm it's not just your "sending" server?
The bounceback should have info in it on the cause, and DKIM issues should result in a complaint response from the denying recipient server.
Don't know how much this fits the community, as you use a lot of terms I'm not inherently familiar with (is there a "welcome guide" of some sort somewhere I missed).
Anyway, Wikipedia moderators are now realizing that LLMs are causing problems for them, but they are very careful to not smack the beehive:
I just... don't have words for how bad this is going to go. How much work this will inevitably be. At least we'll get a real world example of just how many guardrails are actually needed to make LLM text "work" for this sort of use case, where neutrality, truth, and cited sources are important (at least on paper).
I hope some people watch this closely, I'm sure there's going to be some gold in this mess.