Yahoo mail itself is not "down" nor has it been. For the last six weeks ago it has not pushed emails to any number of different devices across all providers, including my iPhone and iPad. There are threads about it on any number of message boards, including Apple's boards. Yahoo also has a thread which I linked to a page or so back, where they admit it's their problem and the engineers there were supposedly working on it. It's six pages of people complaining about the "push" function not working since late May. It does work for some lucky users and doesn't work for many, myself included.
Again, Yahoo has admitted it is a problem on THEIR end - this is not just a handful of people too stupid to fix their own settings on their own phones, whining about Yahoo. If this had not been the second time this year that Yahoo has not worked on my devices for a prolonged period I would not be publicly complaining. Seeing others posting about the same problem, along with my personal experience of two outages in less than six months, both of which went on for more than a month, led to to post these comments.