Follow along with the video below to see how to install our site as a web app on your home screen.
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I've got it working. Go to your yahoo mail in a browser, click on "your mobile" and follow the instructions. It'll tell you the yahoo mail client isn't supported on HTC Hero but will give you instructions on how to get it to work
It then gives you exact details of how to get Yahoo mail with the built in mail software on the phone. It works great, i use it along with my Virgin mail
Follow this here
Yahoo Mail free POP access Picobit
It works for my two other accounts but not the new one.

Here in the UK, you can get pop no problem IF you have yahoo PLUS.
I *believe* that official imap functionality has been released only to iphone users for their push system.
I know there's a workaround for UK users to set their location to asia, but retain language in english. pop is available without PLUS in asia/

but the option is ace!