Proper email filters for email accounts (not just global discard filters)

It would be great, if not essential, to have email filters within each email account, that would allow, for example, to send certain messages to certain folders.

Sure, most email clients can do this... but we don't want this to happen on the client side, we want it on the server side, so that the user would find the filters applied on each device they use.

cPanel has this function, BTW.

Maybe it would enough to offer a more powerful webmail interface next to Rainloop, which is "pretty" but also "pretty limited".