Why isn't sent Yahoo Mail showing on my Curve 9360 (OS 7. 1)?

Hello,

I just got a BlackBerry Curve 9360, mainly due to the emphasis BlackBerry put on email. Working all over the place, I heavily rely on a phone with strong push email functionality. Unfortunately, I'm not really very happy.

My sent email isn't syncing with my BlackBerry. Email I send from my BlackBerry, I can see in my Yahoo mail Sent folder straight away. However, email that I send on my desktop (via the Yahoo Mail website) isn't showing up on my BlackBerry. Also, there's no Sent folder available either. How can I see this folder on my phone?

Thanks in advance.