Browsing a list of messages by HW arrow keys (like in folder list)

Expected: Browsing a list of messages by HW arrow keys

I have V-construction smartphone LG Wine with numpad and other HW buttons like a normal (smart)phone,
including 4-direction arrow keys and "ok" button in the center of them.

Three situations (functions), from the most important:

I would like to browse
a list of conversations/messages inside folder
or a list of messages inside conversation
by moving a cursor by down/top HW arrows and then pressing HW button "ok".

I would like to go to the prev/nex message (when I have displayed one concrete message)
by pressing left/right HW arrow.

It would be also good to go to the next folder by pressing left/right HW arrow when displayed content of one folder.

Actual behavior: List of folders only

It is possible to browse list of folders by top/down HW arrows and select it by HW "ok" button;
but it is not possible to continue by HW buttons deeper into conversations and messages.

Start by tracing the existing hardware-key handling for the folder list, then inspect how conversation and message screens handle focus and navigation. Done means the up/down arrows and OK button browse and select conversations or messages, and left/right arrows move between messages or folders as described.