[Dovecot] Automatically subscribe to folder?

Hello everybody,

i am filtering e-mails using the cmusieve-plugin. A global script filters all mails tagged by SpamAssasin and moves them into the folder Spam:

if header :is "X-Spam-Flag" "YES" { fileinto "Spam"; }

My problem is that users who did not had a folder Spam until the first time of filtering a spam mail are not automatically subscribed to this new created folder. They have to do this step manually in their mail client.

Is it possible to automate this script and subscribe the account to this folder when it is created by the sieve script?

Regards, Christian