Yes, Mail app does work with my free Yahoo Mail account. I did some more checking and apparently POP access for free Yahoo Mail accounts is now available!
And also, using the mail app, I can just click on the attached audio file and it will play right away (or tap and hold and use app like Oplayer).
Atomic Web Browser does have a download manager, but you cannot directly open it from within the browser! But since the Mail app works, it does not matter anyways! But I really like the tabs feature in Atomic anyway, so that will definitely be my default browser!
Oh, and Yahoo Mail works fine from the Atomic (paid) without changing any settings, so the Lite version must have something missing (or set differently) than the paid version which causes a problem for Yahoo Mail.
Thanks for everybodys help!