[Dovecot] Search results as virtual folders

This may have been asked before - if so I apologize.

Some mail clients - like Thunderbird - can provide a virtual folder or "saved search" to provide a list of mails that match certain criteria.
Obviously, unless special client-side caching is implemented - which Thunderbird (my own client of choice) - does not, generation of these folders take time. Does Dovecot have any provision for generating such virtual folders? Possibly as the result of a sieve script?

Daniel