Autoexpunge on INBOX? And disabling autoexpunge for a mailbox via userdb_import?

[Tom Johnson]

I have autoexpunge working for various special_use mailboxes, but I'd like it 
to optionally be used for users for their inbox as well.  I'd also like to be 
able to disable autoexpunge for some users for certain directories.

Is it possible to specify an autoexpunge period for the main inbox?  And can 
autoexpunge be turned off via userdb_import?


Here's some detail behind my questions:

I have the following in 15-mailboxes.conf, and all is working great for the 
autoexpunge feature for the Junk and Trash mailboxes:

namespace inbox {
  separator = .
  mailbox Drafts {
    auto = subscribe
    special_use = \Drafts
  }
  mailbox Junk {
    auto = subscribe
    special_use = \Junk
    autoexpunge = 15d
  }
  mailbox Trash {
    auto = subscribe
    special_use = \Trash
    autoexpunge = 15d
  }
  mailbox Sent {
    auto = subscribe
    special_use = \Sent
  }
}

And I can change the autoexpunge field for those mailboxes via userdb_import in 
a SQL query - that's working great.

But I would like for some users to expire the main inbox and the Sent mailbox, 
and for others for there to be no expiration.

Imagine a scenario where there are users who get a maximum of 15 days of 
storage - everything older than that should expire out.  Other users are 
standard email users - their inboxes, personal folders, Sent mail should never 
expire.


Adding autoexpunge to the main mailbox gives an error:

namespace inbox {
  separator = .
  autoexpunge = 999d
...
...
}

doveconf: Fatal: Error in configuration file 
/etc/dovecot/conf.d/15-mailboxes.conf line 48: Unknown setting: autoexpunge


So is there a way to add an autoexpunge setting to the main inbox?


And can I set autoexpunge to 0 via userdb_import to disable autoexpunge for a 
particular mailbox?  That doesn't give any error, but does it properly disable 
autoexpunge for that mailbox?


Thanks-

Tom