I can’t edit my previous post, but it’s fixed now for me; as I skipped wp 2.2.x, I missed the issue that occured at that time where all wp-generated posts go to wordpress@mydomain.com instead of admin-user@mydomain.com as in wp 2.1 and earlier.
I added a new mailbox and a forwarding rule, and everything is now working.
Me too – I thought it was a problem with Spam Karma, but even after disabling it no joy. Spam Karma’s daily summaries aren’t coming through either.
I don’t see any errors when I add a comment, there’s nothing I can find in my server logs, and my spam filter is not eating it.