Comment 20 for bug 120672

I've used another email application for years, and the "empty junk mailbox"
entry was both in the main menu (near empty trash) and in the context menu.

Both are useful :
-main entry, when you've got lots of mailboxes, you don't want to look for junk
mailbox ;
-context entry, when you've just checked there was no false positive junk mail,
and want to get rid of all the junk.

As the messages are junk, and are known to be junk, I see no point in moving
them from junk mailbox to trash instead of just deleting them.