Fileinto problem with sieve on a shared mailbox with altnamespace enabled

[Nic Bernstein]

Folks,
I've just added a sieve script like this to file some automated messages
into a specific client-related mailbox:

    #
    # Sieve script to put customer Rancid messages into specific client
folders
    #
    require "fileinto";
   
    if header :contains ["from"] "rancid at example.com" {
      fileinto "tech.support.rancid-example-com";
      stop;
    }
    if header :contains ["from"] "rancid at example.net" {
      fileinto "tech.support.rancid-example-net";
      stop;
    }
    ### End Script ###

Our shared folder hierarchy looks like this:
    tech (\HasChildren)
    tech.support (\HasChildren)
    tech.support.rancid-example-com (\HasNoChildren)            
    tech.support.rancid-example-net (\HasNoChildren)

However, when sieve runs the script, I get this error:
    Apr 21 12:13:27 ujiji cyrus/lmtpunix[18149]: sieve runtime error
for  id \
        <20140421171322.0BAB12955C6 at monitor>: Fileinto: Mailbox does not
exist

I suspect that altnamespace is the culprit, but if that's the case, what
would the proper name for the destination mailbox be?  Would it be
"Shared Folders.tech.support.rancid-example-com"?  Not sure what to do here.

Thanks in advance for any and all help,
    -nic

-- 
Nic Bernstein                             nic at onlight.com
Onlight, Inc.                             www.onlight.com
219 N. Milwaukee St., Suite 2a            v. 414.272.4477
Milwaukee, Wisconsin  53202