I had to reset my mum's password on Sunday it seems clear.net.nz email is the same delay (up to 2 hours I was told, actually took 20mins).  I suspect behind the scenes its a bit of a mess of a large collection of separate old servers from each ISP that was bought out. They probably use cron to update the passwords on a timed basis, say once per hour.    I also suspect they now dont run an up to date anti-spam engine on them either if the quantity of spam via Paradise.net.nz is any indication.