[Dovecot] unknown namespace with Mac OS client

[Kenny Dail]

> Actually, I can't test it out.  I've upgraded to OSX 10.4, and the  
> problem with Mail.app (now 2.0.7) appears to be fixed.
Interesting... Because it's broken on my systems with 10.4 and Mail 2.1
-- 
Kenny Dail <kend at amigo.net>