When an entry gets caught in the spam filter, no notifications get sent out (that's probably ok, but maybe an option to send the admin notification that there is spam to check). But if you find something that is not spam and mark it as such, the notifications should go out as if they just got submitted, at least any Notification to User that is set up. We're using it in a way that they really need to get that email. We're disabled akismet for now since this doesn't seem to happen.