Some users may still have trouble accessing their accounts. We’re working through the night on this. See http://t.co/U66mUNtEvO for more.
— YMail Team (@yahoomail) December 12, 2013
Earlier in the night, the Twitter feed reported some progress, saying 30 percent or so of the emails sent during the outage had been delivered. The help page linked in that tweet shows no progress since Wednesday night. ZDNet is calling this Yahoo Mail’s “worst failure yet,” and All Things D says it’s a “full-scale disaster.” From Kara Swisher’s All Things D article: