Windows only: One major annoyance for many Yahoo Mail users is that Yahoo doesn't provide POP access to your email without a paid account. Free, open source application YPOPs! runs in the background of your computer and similates POP access so you can download your Yahoo email to you desktop email client, like Thunderbird. Setting up YPOPs takes a little doing, so head over to the How-To Geek's guide for an illustrated step-by-step. It's no IMAP, but it's better than nothing, especially if you just want to backup your Yahoo mail for free. YPOPs is free, Windows only.