If you use Thunderbird as your email client, a good alternative is Thunderbird "WebMail"
http://webmail.mozdev.org/Go to the forum page and get the most up to date betas of both the add-ons you need:
http://groups.google.com/group/thunderb ... sion/filesCurrently it is
web-mail-1-3-3b3.zip
yahoo-1-4-0b13.zip
They install as add-ons under Thunderbird.
You will notice there are 3 selections in the yahoo component for whichever version of Yahoo Mail you are running.
It will send and receive once you get it setup correctly (don't know about attachments, however).
Until Ypops gets fixed for good (with the new Vmime), this may be a decent alternative.
Freepops also seems to be updated frequently.
http://www.freepops.org/enFinally...................
You can pick your most important Yahoo address(es) and buy the $20 a year service which works like a champ!