Comment 9 for bug 581330

While I would still really like to see a simple, straight-forward way to just:

[x] 'Disable Tabs'

you can almost accomplish it by simply:

1. Set Tools > Options > Advanced > Reading & Display > Open messages in

to 'A new message window'

and

2. Open the config editor (about:config) (press Alt+C), and set 'mail.tabs.autoHide' to true.

Now the only things that will open in a tab are the Calendar, and GLODA search results (which I don't use either).

After a few months working like this, I find it a tolerable workaround.