Doesn't work. But what?

[Andrew Afliatunov]

Hello!
Sorry, if this is the wrong place for my question.

We have Linux Slackware-9.1 mail server with sendmail-13.0. When using 
POP or IMAP all our mail users authenticate in Windows Active Directory 
by means of pam_ldap and nss_ldap.
Also on this server I use SpamAssassin to check mail for spam. It works 
in daemon mode ('spamd') and procmail runs client for it ('spamc') when 
mail comes for user, before putting it in his mailbox. Owner of 'spamc' 
process is the user to which mail came.
Previously I had all the accounts corresponding to Windows AD users in 
/etc/passwd. And check for spam worked fine. But then I decided to 
remove all mail-users' accounts from /etc/passwd. And checking for spam 
stopped working. In procmail.log I see
--
getpwuid() failed: No such file or directory
procmail: Program failure (71) of "/usr/bin/spamc"
procmail: Rescue of unfiltered data succeeded
--
And mail goes to user's mailbox without being checked for spamness.
So, why 'spamc' doesn't see non-local users? Where must be PAM/NSS 
support - in procmail? or in spamd? or in spamc?
I asked this question in spamassassin-users mailing list, but they 
couldn't help. Can you?
Thanks...

-- 
Andrew.