Why is kern.ngroups (static) set to 16 ?

[Martin P. Hellwig]

Hi list,

Some time ago I had a FreeBSD 4-10 (planning to upgrade it to DF) 
installation for my mail/file server.
The users (about 800) on that box make exstensivly use of groups. 
Because I already had the security groups, I thought using those groups 
for e-mail aliasing to multiple users would be a good idea. So I set up 
a couple of scripts which greps the right groups and creates the mail 
aliases in /etc/mail/aliases.

While creating a a couple of new security groups a user became member of 
more that 15 groups (18).

So till now nothing went wrong but at the moment that users gets a 
e-mail sendmail suddenly can't resolve the users name and keeps the mail 
in the que.

After some searching I found that the limit on this system is for users 
to not be in more than 16 groups.
Although I could work around the problem I'm still curios how to really 
solve it.
Could I just change /usr/src/sys/sys/syslimits.h and rebuild the whole 
system including all applications? And would that really work, I presume 
that those limits are not for nothing on hard set to 16, what are caveates ?

Thanks for reading.

--
mph