[Dovecot] Managing IMAP IDLE/Push with Sieve – possible?

[FF]

Hello,

I've been using Dovecot with Sieve for a long time already, and I'm very 
happy with it. Push is working fine too. I was wondering, however, 
whether it would be possible to define a Sieve rule (perhaps using some 
plug-in), such that an IMAP push message gets sent out only for specific 
senders etc.?

Have you come across anything like that?

Thanks a lot,
F.F.