CentOS - Aug 2008 - postfix install error: fatal file /etc/postfix/main.cf: parameter setgid_group: unknown group name: postdrop

Hi,

sys: Centos 5.2 x86_64

Trying to switch from sendmail to postfix I did:

# yum remove sendmail

which resulted in erasing of:
mdadm sendmail-doc sendmail sendmail-cf mutt fetchmail redhat-lsb 


I did then:

yum -y install redhat-lsb.x86_64 postfix

and got this error:

   Installing: postfix                      ######################### [1/2]
postfix: fatal: file /etc/postfix/main.cf: parameter setgid_group: 
unknown group name: postdrop
warning: group postdrop does not exist - using root
warning: group postdrop does not exist - using root
warning: group postdrop does not exist - using root
warning: group postdrop does not exist - using root
   Installing: redhat-lsb                   ######################### [2/2]

I checked and indeed there is no group postdrop on the system.
On an El5 system I see the group.

Thx
Rainer

Rainer Traut wrote:
> I checked and indeed there is no group postdrop on the system.
> On an El5 system I see the group.
>
 Are you using any sort of network authentication system like
NIS or LDAP? Or just standard local files?

nate

Rainer Traut wrote:
> Hi,
> 
> sys: Centos 5.2 x86_64
> 
> Trying to switch from sendmail to postfix I did:
> 
> # yum remove sendmail
> 
> which resulted in erasing of:
> mdadm sendmail-doc sendmail sendmail-cf mutt fetchmail redhat-lsb
> 
> I did then:
> 
> yum -y install redhat-lsb.x86_64 postfix
> 
> and got this error:
> 
>   Installing: postfix                      ######################### [1/2]
> postfix: fatal: file /etc/postfix/main.cf: parameter setgid_group: 
> unknown group name: postdrop
> warning: group postdrop does not exist - using root
> warning: group postdrop does not exist - using root
> warning: group postdrop does not exist - using root
> warning: group postdrop does not exist - using root
>   Installing: redhat-lsb                   ######################### [2/2]
> 
> I checked and indeed there is no group postdrop on the system.
> On an El5 system I see the group.
> 
> Thx
> Rainer
> 

You don't need to remove sendmail, you can just use system-switch-mail 
to set postfix as the MTA.

There is documentation on setting up a basic postfix server (on CentOS 
5) on the Wiki here:

http://wiki.centos.org/HowTos/postfix