cyr_expire or ipurge?

[Joakim Ryden]

Hey folks -

I've been looking into setting up some housekeeping on a Cyrus server 
and I'm a little confused about cyr_expire vs. ipurge...

I've come up with an ipurge event like so:

purgeold      cmd="ipurge -f -d 15 user.*.Junk user.*.Trash" at=0315

Should/could this be rewritten with cyr_expire instead? If so, how? 
Using 2.2.2.

Thanks.

--Jo