Summary of problem:
This is really surprising that it currently functions like this. I'm very curious as to how other people are managing spam and filters because to me it seems to make the spam filter and Akismet completely useless.
You're probably familiar with Reddit's automod filtering options? They seem to be much better than Xenforo's.
Possible solutions:
Conversations need to be treated differently from public comments.
This addon https://xenforo.com/community/resources/ozzmodz-spam-phrases-report.8968/ gave me the idea of reporting the content instead of disallowing it.
That may be ok (though not ideal) for conversations, but spam matches for comments/threads should still be filtered to the mod queue.
Current functionality: filters public content, denies private messages.
1. The most ideal solution would be to filter (instead of deny) private messages into the mod queue, just like with public content.
2. The next best option would be to report messages and filter public content.
3. The next best would be to add a checkbox to only apply the spam filter to public content. Then we could pair that with the addon above to report PMs.
3.5. OR, create a separate spam filter for conversations.
For now, the only "solution" I see is to filter all content to the mod queue for preapproval...