Mac OS X 10.7.4: Apple Mail Rainbow Beachball

With Mac OS X 10.7.4 installed, my Apple Mail now rainbow-beachballs frequently, chewing up an entire CPU for 20-30 seconds at a time when I click on a mailbox, entirely non-responsive. It’s awful— I depend heavily on email and now it’s unusable for any kind of search, or even clicking on a mailbox.

Given the reported volume mounting problems, I’d suggest holding off on 10.7.4.