Postfix + procmail - delivery fails because "can't create user output file" - on CentOS 6.2

Question

I verified that my postfix installation / relaying setup worked. Now I am having trouble with procmail. I have it wired to postfix with the following command:

mailbox_command = /usr/bin/procmail -f -a "$USER"

I have nothing in my procmail config but the following:

LOGFILE=/var/procmailrc/log

And I send an email to a recipient that previously worked (before I attached procmail). Now it fails with error:

Apr  6 14:07:05 localhost postfix/qmgr[15194]: D0C3DFF6E1: from=<[email protected]>, size=938, nrcpt=1 (queue active)
Apr  6 14:07:05 localhost postfix/local[1953]: D0C3DFF6E1: to=<[email protected]>, orig_to=<postmaster>, relay=local, delay=0.05, delays=0.02/0.01/0/0.02, dsn=5.2.0, status=bounced (can't create user output file. Command output: procmail: Couldn't create "/var/spool/mail/nobody" procmail: Couldn't read "//root" )
Apr  6 14:07:05 localhost postfix/bounce[1955]: warning: D0C3DFF6E1: undeliverable postmaster notification discarded
Apr  6 14:07:05 localhost postfix/qmgr[15194]: D0C3DFF6E1: removed

It seems like there is some sort of permissions issue but I do not know what the problem is, nor do I understand how I would go about diagnosing it further. The logfile that I specified is empty, by the way.

How can I make procmail+postfix work?

Solution

i just get into the same and find the answer

$ sudo chmod g+s /usr/bin/procmail

The answer was in
http://www.irbs.net/internet/postfix/0202/1677.html

Comments

[vonbrand]

Please summarize the link, it might go away any time.