[binc] can't save drafts or sent messages on server

Hello,

I just switched to Qmail and BincImap from Sendmail.  When I  
configure Mail.app (on Mac OS 10.4) to save drafts or sent messages  
on the server, those actions fail with a generic error message.  Is  
this functionality known to work in BincImap?  The permissions on my  
Maildir on the server seem to be correct (700, with me as owner), and  
I can see the bincimapd process running as me while I'm connected  
through Mail.app.  Thanks for any thoughts or help.

Eric