Comment 69 for bug 105088

I have checked this again on Ubuntu 13.10 with Thunderbird 1:24.4.0+build1-0ubuntu0 and seems to work as long as the network share is connected through Nautilus already.

When I then go to attach I can choose the already connected network share in the left Places panel.

What does not work is when a network share is not connected already it will simply not appear in the dialog and cannot be chosen.