Virtual folder with 'younger' not updating

[Jonathan Casiot]

I have a virtual folder set up with the following in dovecot-virtual:

INBOX
INBOX.temp
  ALL YOUNGER 86400

The problem is that messages older than 86,400 seconds (24 hours) never 
disappear from the folder. Is there any fix for this apart from adding 
INDEX=MEMORY to the mailbox location in the config file?

I'm running Dovecot 2.2.36 on CentOS.

Regards,

-- 
Jonathan