Subfolders:

Under IMAP Subfolders can only be created beneath the INBOX.

Filter:

A classification of the eMails via the eMail address in the form of "info+ordner/suborder@domain.tld" is not supported at the moment, however we are considering the possibilities of an implementation currently.

We are working on an implementation of Sieves feature via the customer center / Webmail.
Sieve is a powerful filter for IMAP servers.