Unable to log in to ATT-Yahoo webmail; get error reports saying site can't be accessed or site down

Cannot log into my bellsouth.net email addresses; error messages say search engine can't access ATT-Yahoo webmail, the site is down or had address changed; unable to acccess email for more than two hours (reporting this problem at 1:10 p.m. CST Wed Feb. 8 2012, been unable to connect to bellsouth.net accounts since 11 a.m. CST); in addition, for about one week, I have been getting error messages even when able to log in, making me reload the page several times before getting access to my email in boxes.