Thunderbird: getting messageManager for currently displayed email

Hi friends,

In Firefox we use the
gBrowser.selectedBrowser.messageManager to be capable of using the
sendAsyncMessage function to communicate to a proper script.

How
do we get a messageManager in Thunderbird? The window.messageManager
supports only nsIMessageBroadcaster, so there’s no way to send a message
to specific script using sendAsyncManager.

My solution is:

var emailMessageManager = window.messageManager.getChildAt(0);
emailMessageManager.sendAsyncMessage(…)

I wonder if there is a proper way to obtain this messageManager?

Issues resolved on mozillazine thanks to @Lithopsian -

http://forums.mozillazine.org/viewtopic.php?f=19&t=3019013&sid=1691cd01653e1bb12ed263d89404e406