From all that I understand, from attempting to get Yahoo to work correctly through POP3 for years, the only way to use it reliably is to pay for it. A lot of people can't even get shoddy mail coverage with a free Yahoo account. =\
There USED to be a work around by creating your Yahoo through Asia, but I think they might have stopped that too.
I get outages on BOTH yahoo and earthlink. In fact, today I'm experiencing one of these long outages going on 8 plus hours now. I'm not receiving email from earthlink or yahoo.