[Dovecot] expire tool question

[Jakob Curdes]

> Maybe you'll find this thread useful:
>
> http://dovecot.org/list/dovecot/2008-October/034747.html
>   
I already saw this. Unfortunately I do not understand the complete 
reasoning.
If I'm right the thread basically says

- dovecot-expire should log something with mail-debug=yes.
(it doesn't in my case, other than "Module loaded: 
/usr/local/lib/dovecot/imap/lib20_expire_plugin.so")
- hierarchy separator could be wrong
(cannot be my case as I have the folders directly in the user's mail 
directory, no hierarchy there)
- messages might be too young
(The folders are older with messages that are weeks old and I want to 
expire after 7 days. But if I understand it correctly, the expiry DB is 
only built or touched on certain events, which ones would that be? 
Adding a message to the folder? Or is it impossible to expire messages 
present BEFORE expire plugin installation?)

Any hints?

JC