I do not recollect myself when was the last time Yahoo! mail was down. Suddenly yesterday night when I logged into my primary Yahoo! mail account I got a nice error with the message Can’t talk now. System’s down (see the screen shot in the side). I tried the same account couple times ..and the same error repeates.

Interestingly when I tried to login with other email account then that started working and re logging in back the primary one still produced the same error….May be a perticular region or colo servers seemed to be down during that time.

Good that I captured the screenshot of the error as shown in the right side. 
Yahoo! Mail Down