[Dovecot] Shared Folters with LDA/Sieve

Hello,

i'm searching for a way to use Shared mailboxes with Sieve Filtering.

I need global email addresses like: info@foo.tld contact@foo.tld help@foo.tld

Every address with own Sieve-rules for filtering and sorting of incoming mails.

Now every user needs access to this folders, but how? How should i create the "global" addresses?

I already found http://wiki2.dovecot.org/SharedMailboxes/Public , but that's just a public namespace.

Is there any FAQ available for this?

Thank you very much Dieter