Create SPAM folder when Maildir created

We have users who want to not use webmail, they want to use an email client. That's ok, except the Maildir is not created when a new email user is created. However, you can make that happen by sending a signup email, so all is well and good.

EXCEPT.

They cannot subscribe or access the SPAM folder until they get their first spam, which they won't know of course since they are not subscribed to it.

So, the missing piece is the SPAM folder needs to be created whenever the Maildir is created. This would greatly simplify things for new users wanting to use an email client of their choice.

Can you get this done?