Ubuntu server - mail server

[Nalin1990]

I got an error becauese  

/var/spool/mqueue

this directory is not there i executed chmod 755 /var/spool/mqueue

but no result then I created back /var/spool/mqueue directory but still my problem is there

please answer my problem

P.S. This thread has been moevd from HP-UX > Messaging to Linux > sysadmin. - HP Forum Moderator

[Matti_Kurkela]

You cannot chmod something that does not exist. If you ran "chmod 755 /var/spool/mqueue" when /var/spool/mqueue was not there, you should have received an error message from the chmod command.

So you should *first* create the missing directory, *then* assign it the correct owner, group and permissions:

• the chown command can assign either just the owner (chown <owner> <file_or_directory>), or both owner and group (chown <owner>:<group> <file_or_directory>)
• alternatively, the chgrp command can be used to assign the group
• and the chmod command is used to assign the permissions (historically called "file mode", hence chMOD).

I don't have an Ubuntu system at hand, so I cannot check the actual correct owner/group settings, but typically /var/spool/mqueue should have owner=root, group=mail.

In other words: either

mkdir /var/spool/mqueue
chown root /var/spool/mqueue
chgrp mail /var/spool/mqueue
chmod 755 /var/spool/mqueue

 or

mkdir /var/spool/mqueue
chown root:mail /var/spool/mqueue
chmod 755 /var/spool/mqueue

 would be the correct sequence of commands.

NOTE: if you get an error message saying that /var/spool/mqueue has _unsafe_ permissions, it means the directory is accessible to _too many_ users/groups. In that case, you should think about taking away some permissions instead of adding more. Some installations of sendmail can require "chmod 700 /var/spool/mqueue".

Also, in POSIX-compliant filesystems (= most native Unix and Linux filesystems) having write access to a directory usually means that it is possible to delete, rename or move anything in that directory.  So if /var/spool (or even /var) is writeable by someone other than root, then /var/spool/mqueue may be "unsafe", no matter what permissions /var/spool/mqueue actually has.

[Dennis Handly]

> then /var/spool/mqueue may be "unsafe",

Unsafe in that the directory path can be changed to "hide" it.