NIS and groups

[Adam C Powell IV <hazelsct@mit.edu>]

Greetings,

To get Netscape movemail working on my NIS server, I did:

adduser hazelsct mail

so NS could write a lock file to /var/spool/mail.  However, when I try
to do this on the NIS clients, I get

# adduser hazelsct mail
Adding user hazelsct to group mail...
usermod: hazelsct not found in /etc/passwd
adduser: `usermod -G mail hazelsct' returned error code 6.  Aborting.
Cleaning up.

Of course hazelsct isn't in /etc/passwd, because hazelsct isn't a local
user!

Same goes for group floppy, to write to the floppy disk, and numerous
others.

How do I set things up so that either it will recognize group
memberships on the NIS server, or else allow me to add NIS users to
local groups?  Do I need to eliminate local groups like floppy, mail,
etc?

System info: latest potato on x86.

TIA,

-Adam P.