Comment 3 for bug 1507652

Bob Briscoe (m-bob-q) wrote :

Solution: With the focus on the open compose window, select from menu: Tools > Mail & Newsgroups [Ctrl+1]

There are related inconsistencies though.
* If an email is opened for reading in a new window, the shortcut key changes: Tools > Mail & Newsgroups [Alt+1]
* If only search, message filters, activity manager and preferences windows are open, no top level menus are visible and neither [Ctrl+1] nor [Alt+1] does anything.

The latter is a bug. However, there is a work-round that works in the other cases as well:
* Launcher > right click Thunderbird icon > "Compose New Message", which then gives access to the first solution above.

This problem is irritating for me, because I often have large numbers of Thunderbird windows open, and until I found the above solutions/workrounds, if I accidentally closed the main window (which I have done many times), in order to reopen it, I had to close all the other windows, thus losing track of all my work-in-progress when I restarted Thunderbird.