What the heck.... Spamass-milt on my work machine

[Derek J. Balling]

From my home (working) installation:

$ cat /etc/default/spamass-milter
OPTIONS="-m -u nobody"
$ cat /etc/default/spamassassin
ENABLED=1
OPTIONS="-c -m 10 -D"

From my work (not working) installation:

$ cat /etc/default/spamass-milter
OPTIONS="-m -u mail"
$ cat /etc/default/spamassassin
ENABLED=1
OPTIONS="-c -m 10 -D"


From my work (not working) log file, when it encounters an alias (e.g., 
where address@hidden points to address@hidden):

Jul  9 11:32:22 whitechapel spamd[6587]: logmsg: handle_user: unable to 
find user 'whois'!
Jul  9 11:32:22 whitechapel spamd[6587]: handle_user: unable to find 
user 'whois'!
Jul  9 11:32:22 whitechapel spamd[6587]: logmsg: Still running as root: 
user not specified with -u, not found, or set to root.  Fall back to 
nobody.
Jul  9 11:32:22 whitechapel spamd[6587]: Still running as root: user 
not specified with -u, not found, or set to root.  Fall back to nobody.
Jul  9 11:32:22 whitechapel spamd[6587]: logmsg: fatal: setuid to 
nobody failed
Jul  9 11:32:22 whitechapel spamd[6587]: fatal: setuid to nobody failed

... and, according to `ps`, it IS running with -u:

$ ps auxwwwn | grep spam
0  5851  0.2  4.1 23316 21300 ?       S    11:26   0:03 /usr/bin/perl 
/usr/sbin/spamd -c -m 10 -D -d --pidfile=/var/run/spamd.pid
0  5865  0.0  0.2  4564 1116 ?        S    11:27   0:00 
/usr/sbin/spamass-milter -p /var/run/sendmail/spamass.sock -m -u mail
0  5866  0.0  0.2  4564 1116 ?        S    11:27   0:00 
/usr/sbin/spamass-milter -p /var/run/sendmail/spamass.sock -m -u mail
0  5867  0.0  0.2  4564 1116 ?        S    11:27   0:00 
/usr/sbin/spamass-milter -p /var/run/sendmail/spamass.sock -m -u mail

What am I doing wrong here?

Cheers,
D