[fory]

Done,
for me if remove the "if not mailbox['has_children']" line 65 addon.py show me the IMBOX and other folder.

items = [{
'label': _format_label(mailbox),
'path': plugin.url_for(
endpoint='show_mailbox',
mailbox=mailbox['raw_name'],
)
} for mailbox in client.get_mailboxes() if not mailbox['has_children']]
return plugin.finish(items)

-------------------------------------------------

items = [{
'label': _format_label(mailbox),
'path': plugin.url_for(
endpoint='show_mailbox',
mailbox=mailbox['raw_name'],
)
} for mailbox in client.get_mailboxes()]
return plugin.finish(items)