ipurge doesnt work for mailbox pattern

[Ramprasad A Padmanabhan]

Hi,
   I want to delete all older mails from my cyrus mailboxes

   If I run ipurge like
         ipurge -d 60 -f user  then it works file
 
   But If I run ipurge with a pattern it fails 
         ipurge -d 60 -f user/someuser  

I tried user/someuser or user.someuser etc ... doesnt help 

Thanks
Ram