^Thunderbird works fine for me under SL (and under Windows XP Professional too, for that matter). It has a WebMail extension that can access Yahoo WebMail accounts (and accounts from various other WebMail providers: http://webmail.mozdev.org/
). You can find out more in mozillaZine: http://kb.mozillazine.org/Using_webmail ... ail_client
(notice the link on that page to a dedicated thread in the mozillaZine forum on the WebMail extension). From time to time the WebMail providers change their software so the extensions have to be changed to keep pace, but the aforementioned mozillaZine thread and a Google group http://groups.google.com/group/thunderb ... ion/topics
keep people up to date on the latest developments).
See the instructions in the SL Wiki article http://wiki.sabayonlinux.org/index.php? ... al_boot_PC
(scroll down to the relevant section in the article) for how to set up Thunderbird with WebMail (the instructions are for using it with Hotmail, but should be similar to what you'll need to do for other WebMail providers).