kern.openfiles limit on FreeBSD

Hi,

I have just upgraded to FreeBSD 5.3-RELEASE-p5 and have problems with
the number of open files in the system.
I am using DCC 1.2.67, SA 3.0.2 and sendmail 8.13.1

At a certain point in time kern.openfiles starts to increase until I get
"too many open files" error messages.  I have a two processor machine
with two Gig memory. The load on the machine is very low and it is only
handling mail.
When I stop the sendmail process kern.openfiles does not decrease.  But
restarting dccifd will decrease the value from >4000 to something like
300 

Here are some other kernel variables that may be of interest:
kern.maxfiles: 15000
kern.maxfilesperproc: 7408
kern.ipc.maxsockets: 8232

I do not know if this is a DCC, SA or OS issue.  Has anybody seen a
similar behaviour.

Regards,
Ludger Bolmerg

Ludger Bolmerg
Munich Re
IT164 Network Services