Apple Mail Export - Flawed?

When attempting to export mailboxes for the purpose of freeing up space on my iMAP server, the esport feature does not appear to have a progress indicator. When you first "kick off" an export a .partial file is created and then after some time an INBOX file.


First where is a progress indicator to let you know once the export is complted.


Second what are the files that are created? This is what I'm seeing: (INBOX and Sent Messages.mbox appear to be folders)


INBOX

Sent Messages.partial.mbox

Sent Messages.mbox

mbox

table_of_contents