Re-apply Sieve filters

[Harri Porten]

Hi!

I bet this is a Sieve user FAQ but I assume the answer is 
implementation-specific:

Is it possible to re-apply Sieve filters to an existing folder? Even if 
it's not possible to do with Aox I'd be interested to hear and discuss 
whether some Sieve extensions exist and how this could theoretically work.

Thanks,

Harri.