A Class on the Net for Librarians with Little or No Net Experience


"Never speak what you don't think -- or all you do!"

-- Anonymous

Everyone who sends and receives email has an email address. Do not confuse the email address with a password. Your email address is public; it's like your mailing address. You give it to others so that they may reach you. Your password is private and you shouldn't give it to anyone.

Email addresses are important for all they can tell us. At first glance, these addresses appear strange and sometimes incomprehensible. However, there's a logic to them that you need to understand. For example, here's mine:


Let's take a closer look at it. Every Internet email address has three parts:

  1. a user name
  2. an "at" sign (@)
  3. the address of the user's mail server, or "hostname"
The hostname is the string that follows the @ sign and which may or may not be capitalized. The hostname incorporates the domain name, which corresponds to an institution or an organization's computer network.

The hostname for the University of South Carolina CMS mainframe, where I have a 'shell' account for Internet access, is:


sc.edu is the 'domain name' for the University of South Carolina; every computer on the USC system uses this domain name.

When reading and deciphering an email address, the trick is to read it in reverse order, from right to left. The letters at the far right-hand end of the hostname are the most general designation and tell what kind of a site it is:

Because the Internet was created in this country, US was not originally assigned to U.S. domain names; however, it is used to designate state and local government hosts, including many public schools. Other countries have their own two letter codes as the final part of their hostnames, e.g., UK for United Kingdom; CA for Canada; FR for France, etc.

The rest of the hostname, still reading right to left, lists the "subdomains" that tell you the name of the institution where the mail server is actually located, perhaps indicate a department or division, and finally indicate the name of the mail server's machine.

Let's look at the University of South Carolina's hostname again:


Reading from right to left, you can see that edu tells us this is an educational site. SC stands for the University of South Carolina (SC.EDU is the domain name for the University, and all Internet hosts at the University end with the domain name sc.edu); finally, vm is the name of the University CMS mainframe computer, where I have an account.

Now, look once more at my email address. My assigned account, or "userid," at the University is L700007 and so my email address is:


It's easier to understand now, isn't it? Yet, you may have already noticed this is not the address I normally use. In fact, I have two other addresses as well:

  1. My alias is: ellenc@sc.edu
    The University gives me the option of creating an "alias" for myself. This is really a "customized" or "personalized" address, which makes it easier for others, and for me, to remember.

    If you wish to email me personally, you can reach me at either one of my personal email addresses: L700007@vm.sc.edu or ellenc@sc.edu

  2. My BCK2SKOL ("Back-to-School") address is: Bck2eln@sc.edu
    If you have a question or comment pertaining to BCK2SKOL, you can reach me and/or my collaborator, Miriam Mitchell, at our shared BCK2SKOL discussion address, at: Bck2eln@sc.edu

    We set up this mailbox specifically to handle comments, corrections, criticisms, kudos, whatever -- concerning BCK2SKOL. We can't promise to solve your problems, but we'll try to answer your questions if we can and we'd really like to read your reactions to the course and its content.

    I just have one simple request to make of you -- please don't email us with questions about your individual systems (which I can't answer anyway) -- that's what your "sysop" is for. However, if you do have a networking-related problem that you just can't solve, Miriam is a "miracle-worker" and she has graciously agreed to help you if she can. Just remember to be reasonable and try to keep it short and sweet; we're both on the University payroll but, unfortunately, nobody pays us for BCK2SKOL.

Now, let's look at some additional email addresses supplied by Patrick Crispen, author of the online "Roadmaps" workshop. Can you decipher this email address?


Reading from right to left, the gov means it's a U.S. Government address. Of course, NASA means the National Aeronautics and Space Administration. MSFC stands for George C. Marshall Space Flight Center in Huntsville, Alabama. HQ is self-explanatory.

Can you read this address?


(I bet you could, especially if you knew that saceur stands for Supreme Allied Commander-Europe)

Says Patrick, the best rule of thumb about Internet addresses is this: "if the address is not of the form described above and does not end with one of the standard top level domain abbreviations or country codes, the address is NOT an Internet address. You may still be able to send mail to non-Internet addresses through a gateway though." (Look for instructions at the end of this lesson on how to access an information resource online that explains how to connect to non-Internet addresses.)

One more point. When you receive an email message, many of you will notice that it is preceded by a "header," a string of seemingly endless lines of what Patrick likes to call "computer-ese gibberish." Remember when I pointed out that traffic on the Internet follows a completely random route? Well, the header records that route and tracks all the places your message went before it finally reached your mailbox. Most of the time, you can safely ignore headers and scroll right down through them. They are primarily of interest only to the people who run your system. (Some software packages do not display headers, in which case, you won't see them at all.)



There's plenty of information on email and email software in:

     Levine, John R. and Margaret Levine Young.  _More Internet for

       Dummies_.  2nd ed. IDG Books, 1996.


Following are some additional WWW resources related to this lesson:

* "BCK2SKOL" is a free electronic library classroom created by Ellen Chamberlain, Head Librarian, University of South Carolina Beaufort, and Miriam Mitchell, Sr. Systems Analyst, USC Columbia. Additional support is provided by the Division of Libraries & Information Systems, University of South Carolina Columbia.

Your feedback and support for BCK2SKOL are appreciated; please email link updates, suggestions and comments to: eechambe@gwm.sc.edu

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Links checked 9 March 1998. See the BCK2SKOL homepage for course update details.
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URL: http://www.sc.edu/bck2skol/fall/lesson5.html