[Dovecot] dovecot-shared being ignored?

[bhayden at umn.edu]

So, I'm working on a shared folder. Everything is nice except for one bit. 

My dovecot-shared file in the Maildir is either being ignored, or doesn't 
work the way I think it does. Any messages copied into the Maildir using a 
mail client are mode 660 and owned by the user who did the copy. Perms on 
the dovecot-shared file are 700 (I'm using Solaris ACLs in addition to the 
Dovecot ACLs in order to prevent unauthorized access via means that don't 
pass through Dovecot's IMAP server... ie SFTP/SCP, and so I'm using 700 
with a rwx mask and access to the file set per user in the Solaris ACL).

The message files being created 660 means they are accessible via SFTP/SCP 
to anyone in the group, and we have a single one for (nearly) all users. 
This is not really acceptable, so if anyone can offer guidance on the 
dovecot-shared that'd be great. I checked the wiki, and it has very minimal 
information.

-Brian