I want to set up a POP3 mail server. I just bought redhat 9 a few days ago and I don't know much about it. Can someone help?

Before you tackle that question you might want to explain what an editor is and which one should I be using.

I have a Linux book that reads, "Once you have installed a POP server, you add accounts to it by simply adding standard user accounts on the host it is running on."

How do I do that.

To get a handle on the Linux operating system, I suggest bookmarking/downloading:
Rute User's Tutorial and Exposition
Linux Newbie Administrator Guide

If you installed midnight commander, it has a nice text editor. You can launch it from an x terminal or a virtual terminal with the command mc.

If you installed pine, you also have pico.

# Common e-mail tools
sendmail - postfix - sends mail to local users (and internet when configured correctly)
fetchmail - gets mail from internet accounts (non-Hotmail type)
procmail - sorts and delivers into separate mailboxes
mutt - mail client that sucks less than all the others
Email the Linux Way
Suresh Ramasubramanian's email guide
The Linux Mail User HOWTO
The Linux Electronic Mail Administrator HOWTO
SquirrelMail web mail

For an editor, I just use "vi". I'm old school like that. As far as adding e-mail accounts, that's easy. Like you said, add users to the system where the mail server is and you would be all set. To add users, just use the "useradd" command. Do a "man useradd" to get the options you want. That should take care of that. As far as a server, set up an MTA, such as Postfix or Sendmail. Then, to set up pop3 access, go to /etc/xinetd.d/ipop3 and change disabled = yes to disabled = no. Then, restart the xinetd service. If you're running RH, do this by "service xinetd restart". Hope that helps.

Chris