[Dovecot] Master account

[Diego M. Vadell]

Hi,
   Is there an administrator o master account in dovecot, which could be able 
too access all mailboxes? I need to periodically delete some emails (older 
than a number of days). I wanted to use imapfilter, a program that uses imap 
to access mailboxes to do that, but as the users can change their passwords, 
I can't do it. Is there a way to do that?

Thanks in advance,
 -- Diego.