Using my BB when I receive emails and I delete them using my BB they get deleted in my yahoo account, as expected.

BUT when deleting my SENT messages using my BB I go to my yahoo account and they don't get deleted.

Anyone know how to fix this?

I tried removing the battery for 20 or so minutes and that did not help.

No one seems to know?

Yahoo doesn't have the full integration over BIS the way other accounts on BES have it. To get true email sync like you're expecting you need a corporate BES connection. Until fairly recently NO email behaved like this at all over BIS, but companies have been upgrading their servers to help make it possible.

Correct, email redirection is only done for your inbox and nothing else on BIS.

Thanks guys, makes sense now!