… at least for the paid Yahoo Mail Plus users like me. After spending several days trying in vain to download all my 35000 emails via POP3 to Outlook 2010, I was about to switch to Gmail permanently (since from Day 1 it has offered free IMAP, which is much more reliable and faster) when I stumbled across this link. In particular, see the reply from 11/18/2010. These settings worked like a charm for me:
Incoming: imap.mail.yahoo.com SSL: True Port: 993 Outgoing: smtp.mail.yahoo.com SSL: False Port: 587 Outgoing server requires authentication:Checked Use same settings as incoming server
I don’t know if it works for regular (free) Yahoo Mail accounts, or if it’s officially supported even, but I guess I will keep my paid account a little longer!