Ipfw and qmail-smtpd, connections getting stuck - FIN_WAIT_1 FIN_WAIT_2

[Vini Engel]

Hi guys,

I was wondering if anyone here has had anything similar with ipfw and
qmail-smtpd. I have a FreeBSD 5.3 and 5.4 box running qmail and often I
can see many connections with FIN_WAIT_1, FIN_WAIT_2, LAST_ACK, CLOSING.

On this box I have some ipfw limit rules to allow incoming connections 
and normal keep-state rules to allow outgoing connections. In the 
beginning I thought it was being caused by the sysctl 
net.inet.ip.fw.dyn_keepalive. I then disabled the keep-alive, it seems 
to have helped but still there are many connections stuck at the FIN stage.

Does anybody have any tips on this?

Thanks a lot
Vini