sendmail + spamassassin on FreeBSD 5.2

[RJ45]

Hello,
I am running latest sendmail + latest spamassassing thru the
spamass-milter mechanism on FreeBSD.
When users send mail it keeps like 10-15 seconds before the mail is sent
and this is annoyign for users.
I inspected the sendmail logs and I saw that spamassassin keeps mroe than
10 second to process a single message for spam.
My machine is a Dell poweredge 2650 with dual xeon 2.4GHz.
I disabled rbl checks in spamassassin.
Anyoien noticed this problem ?
I don;t know how to increase spamassassin log level, anyway I would like
to disable SPAM checks for mails which originate from my LAN, but I can;t
figure out how to do it.
Anyone had tried it before?
thanks

Rick