[MlMt] SmartMailbox configuration glitch?

[AC-Martin]

So I'm now 'deepening' my smart mailbox setup.  I've started with the 
Sent folder.  I wish to have the sent messages organised by subfolders 
according to those to whom I've sent messages.  So I enabled 'Submailbox 
for each unique value of' and selected 'Recipient...Domain'.

The thing is that I'd expect the 'Mailbox name format:' to change to 
reflect the domain names, but it's stuck at ${from.address}.  It would 
be a lot more useful, if it were to display the various domains messages 
that are being sent to?  I tried manually formatting the format string 
to "${to.address} but ended up with a crash. :)

—
Curtis acm