Postfix on a laptop

Is anyone using Postfix on his laptop?
If so, how do you get your disk to spin down?
I'm using Debian's package and am having trouble because the time-stamp on
the /var/spool/postfix/public/pickup pipe is updated every minute, thus
preventing my disk to spin down. Similarly the time-stamp on
/var/spool/postfix/public/qmgr is updated every five minutes.

I only use Postfix for outgoing mail (the machine never receives mail from
outside and has no local mailbox).

Of course, I can change the wakeup frequency of those programs, but it
seems like it would be even better to just make sure those timestamps
aren't changed (I'm enviously seeing all those sockets next to those two
pipes, with their mtime unchanged since boot and wishing that those pipes
were sockets instead).

I'm rather inexperienced when it comes to Postfix, so I have no idea where
to start.


Stefan