Yousuf Khan wrote:
On 4/27/2020 12:04 PM, Frank Slootweg wrote:
If there are 580,000 files in the News folder, then you've probably
configured your Thunderbird News account(s) to use one file for each
article instead of one file for each newsgroup.

If so, it's probably best to bite the bullet and convert to one file
per newsgroup. That probably needs an export and (re-)import and
probably will be time-consuming, but at least then you'll solve the
actual problem.

FYI, my setup - not Thunderbird - has nearly a million articles, but
only some 600 files.

Yes, that is exactly the problem, I was getting at. Does Thunderbird
have a new news file format available? My assumption was that
Thunderbird only does 1 file/message? What's the option to convert?

It's not a new News file format, it's a different format.

You set the format in the News account: Tools - Account settings -
your news account in the left pane - 'Server Settings' page -
Message Storage - Message Store Type:. This field *should* be set to
'File per folder (mbox)'. Yours is probably set to 'File per message
(maildir)'.

For your account - i.e. an *existing* account - you probably cannot
change this setting, i.e. you can only set it when you create the
account. Hence my comment about exporting and (re-)importing. If you
cannot change the setting, you will have to export all the articles from
your current account and then re-import all articles into a new account
with 'Message Store Type: File per folder (mbox)'.

The basic Thunderbird program has no export facility and only very
limited import functionality.

For import of e-mail (from Windows Mail), I have used the Thunderbird
ImportExportTools [1] Extension, but I have not used it for News and not
for export.

ImportExportTools can export on a per-folder basis, so you could try
to export just one folder/newsgroup and then import it into a new
account to see if it works for News. Exporting is a copy-type operation,
i.e. the source remains untouched, and if you import to a *new* account,
the old account remains untouched. IOW, it's a totally safe operation.

If ImportExportTools can not solve your problem, you'll probably have
to search the Thunderbird support site(s)/forum(s) or/and post there.

[1]
https://addons.thunderbird.net/en-GB/thunderbird/addon/importexporttools/?src=userprofile