Add an entry to the aliases text file for each mailing list, where the alias field contains the name of the mailing list, and the recipient field contains a comma-separated list of all of the recipients of the mailing list.
To create an object in Active Directory, you have to specify the objectClass, relative distinguished name (RDN) value, and any other mandatory attributes that are not automatically set by Active Directory. Some of the automatically generated attributes include objectGUID, instanceType, and objectCategory.
You need to know how to create system users for programs like Postfix, Apache, or Squid. These programs should have their own unique user accounts and not just all pile into “nobody.”
Both adduser and useradd can do this. adduser works like this:
# adduser —system —no-create-home —group squid
Adding system user squid…
Adding new group squid (109).
Adding new user squid (109) with group squid
Not creating home directory
Check your work:
# cat /etc/passwd | grep squid
squid:x:109:109::/home/squid:/bin/false
Even though it lists /home/squid, a home directory is not created.
Here’s how useradd does it:
# useradd -d /dev/null -g squid -s /bin/false squid
The nobody user is the default for a lot of daemons and processes that need a system account, but an increasing number of applications require their own unique users. Use a unique user whenever possible, because it’s a good security practice. The nobody account is a common cracker target, and you don’t want to expose all kinds of processes and daemons to a common point of attack.