Sieve filtering - any approach for roundcube

[praenti]

Hi,

because I like how RoundCube works in comparison to for example Squirrel I wanted to ask if there is any approach to implement a sieve filtering support?

Because I have this requirement for usage Roundcube for our local Internet-Computer Club, I need this functionality as soon as possible for switching from terrible Squirrel to cool RoundCube.

Cheers,
Michael