Mail server with 3500 active accounts

[Matt Juszczak]

We're running a mail server with 3500 active accounts.  Are there any 
kernel variables I should set with sysctl in loader.conf that will make 
the system more efficient, etc.?  Right now I'm just running with the 
defaults.

I found a site online that says if you run hundreds of postfix processes 
then you need to change things.  Our count right now is about 34 when I do 
ps auxw | grep postfix | wc -l ... but of course that includes other 
processes like clean, etc.

Thanks!

-Matt