I enabled the Akismet plugin in Vanilla 2.8 and signed up for an Akismet account. It's flagging some spam, but there are misses and false positives. That's fine and expected, but the stats on the Akismet console always show 0 for Missed Spam and 0 for False Positives.
I would guess what would be required is that Vanilla needs to send info to Akismet when something is marked as spam by a non-Akismet method, as well as sending info to Akismet when something is marked as non-spam in Vanilla.
Or am I missing something?