I have a configuration where 3 of my accounts all appear under the "Unified Folders" in Thunderbird 3.1. About half of my mails get sorted into various folders under "Local Folders", and the other half remains in the default inbox, which seems to be under local folders.
After having gone through an exercise to delete some old emails, I have noticed that the space used on disk doesn't seem to add up. I am aware of how to permanently delete messages, as well as how to compact folders, so that is not my issue. The issue seems to be that aside from the "Local Folders" being quite large on my hard drive, the inboxes for the 3 mail accounts that I have configured are also quite large. This shouldn't be the case, unless these emails are copied (not moved) from their relevant inboxes to Local Folders, something which is done automatically by Thunderbird. Unfortunately there seems to be no direct way for me to view the contents of these inboxes, other than going through "Local Folders", or the "Unified Folders". Clicking the left or right arrows on the folder pane cycles through variations of these, but I do not get to see the "raw" inbox for these separate accounts, where I might be able to manually delete and compact.
What am I doing wrong / how can I clear out these inboxes?