[ingo] default blacklist behavior

[Liam Hoekenga]

I'm told that there's already a way to do this (provided it's supported 
by the backend being used), but I can't figure it out.

By default, messages sent by blacklisted addresses are deleted ("Delete 
message completely").  I'd like to set a SITE WIDE default such that 
blacklisted messages are moved to a different folder.

I don't see an option for this in backends.php, conf.php or prefs.php.

We're using this Sieve backend.

Even if this isn't supported by the Sieve backend, I can't figure out how 
you would make "deliver to folder" the default for blacklist action 
instead of "discard".

Liam