How large is your /var file system?
Code:
Filesystem GB blocks Free %Used Iused %Iused Mounted on
/dev/hd9var 0.25 0.19 24% 928 3% /var
There is potentially quite a bit that can take a lot of space from var. The mail files are one example. If you run MQSeries the logs and error files can be stored under /var/mqm. These can take up a LOT of space if not monitored. The spool directory as you mentioned has the mail, syslog, printer queues and other stuff. What files do you have in the mqueue directory that take up so much space? The examples you have provided are not clear.
All depending on what you have already, the easy solution is to grow the /var file system and be done with it.