I read probably 98% of my mail in the message pane (f8). I use neither the tab or the window unless I have a particularly dense lot of text to work my way through. Then I will use a tab.

I do admit I rely extensively on the compactheader add-on to shrink the message header to acceptable levels (1 line) and customized main toolbar to replace the icons available on the message header that I actually use. But that is one of the strenghts of Thunderbird. You can customize it to your liking.

So from my perspective I wonder why you bother to complain about things I do not use to do exactly what you are doing. Reading mail.

I also have absolutely no idea what this statement means. "Why a message doesn't stay in without any opening by default? " stay in what?

If you have no idea why do you pretend to answer? It opens that way by your 'default' only. No way to have it just opened in the pane.

rick27 said

If you have no idea why do you pretend to answer? It opens that way by your 'default' only. No way to have it just opened in the pane.

Apparently you have not spend much time actually using the application.

Do you have the message pane turned on? You press F8. See http://kb.mozillazine.org/Window_layout_-_Thunderbird if click a message in the list and it opens in the message pane in the already open tab along with the mail list and folders.

If you double click on a message it opens in a tab or a window.

Perhaps you might still like to explain that statement "Why a message doesn't stay in without any opening by default? " it is still completely meaningless to me. I have no idea what you are trying to communicate. It is not that I do not know the answer. the collection of words is meaningless.