That depends on the e-mail client you are using. If you are using Outlook
you could ask in an Outlook newsgroup. Select 'Office', then 'Outlook' from
the list on the left. But if you are using Outlook Express you could ask an
Outlook Express Newsgroup. Select 'Windows' then 'Outlook Express' from the
list on the left. If you are using a different sort of E-mail client.then
you will need to find a newsgroup for that product.
Be sure to make it quite clear whether you are setting up the folder (which
is trivial) or you want to automatically send junk mail to it (which is more
complex).