The popular, safer alternative to the Outlook Express mail client Thunderbird, from the Mozilla folks, can be used for more than just POP3 / SMTP mail. If you did not know, Google provides POP3 access access, but all the other popular WebMail platforms do not. Lucky for us, Mozilla has developed Extensions to support the other popular WebMail formats from Yahoo to HotMail to AIM/AOL.
Mozilla has made it fairly easy to setup too. First, you download their base WebMail Extension, and then individual Extensions for only the services you have. After the Extensions are installed, you have a new option, WebMail, in the Add Account interface, which takes you through a Wizard to configure. That's it!.
I setup and tested both Yahoo and AIM/AOL. The only thing to watch for is that you enter your complete email address for the username (i.e. firstname.lastname@example.org not yourname).
If you have not made the switch to Thunderbird yet, this is the time. In addition to the WebMail Extensions, you get a much safer environment (no Internet Explorer integration), and it doubles as an RSS reader.