Using UNH UNIX E-Mail Addresses with ListProc

This document describes how ListProc, as installed here at the University of New Hampshire, interacts with e-mail addresses for the central UNIX systems administered by Computing & Information Services. At the time this document was written, this included the systems: Christa, Hopper, Alberti, and the LiNUX workstations in the public clusters.

If you are reading a printed copy of this document, you will find the latest version available via the World Wide Web as: 

          http://www.unh.edu/NIS/Docs/ListProc/cisunix.html
or by sending the command: 
          get  listproc  cisunix.txt
in the body of an e-mail message to the ListProc@lists.unh.edu server address.

The document you are reading now was last updated on 20-AUG-1997.

Introduction

One of the earliest central UNIX computer systems at UNH, known as "Kepler" was retired during the summer of 1997. At the same time UNH Computing & Information Services (CIS) put into service a new replacement machine, called Alberti, keeping the total complement of central UNIX systems at 3. Alberti, however, was a considerably more powerful machine, so the capacity of the UNIX cluster was substantially increased. Paired with the introduction of this new machine was the creation of a new UNH network identity called cisunix.

About the Central UNH UNIX Machines

As you may already know, Christa, Hopper, and now Alberti, all share the same disk storage areas even though they are distinct and separate machines. This means a person with a central UNIX account name and password can log onto any one of these machines and have access to his/her own files and electronic mail. Sending an e-mail message to any one of these machine's addresses will reach the specified user regardless of which machine s/he happens to log onto. However which machine the user is on is important when sending e-mail since that will determine the sender's return address. For example, if user "abc" logs onto Christa and sends an e-mail message, the return address will be 
            abc@christa.unh.edu
This can be significant when subscribing to a restricted e-mail list. When so subscribed, a restricted list will not recognize the return address of, say 
            abc@hopper.unh.edu
as being the same person although that is indeed the case. In fact even for non-restricted lists this can become a problem when it comes time to un-subscribe from the list or change other aspects of that user's subscription.

New and Simpler Addressing

Beginning in the summer of 1997, CIS took steps that will help to avoid this type of confusion in the future. The new machine, Alberti, is the first in having a new standardized return e-mail address of: 
            @cisunix.unh.edu
In other words, it identifies itself as cisunix rather than Alberti in all return e-mail addresses. In addition, cisunix is now, in effect, an alias for all of the central UNIX systems for inbound e-mail messages. That is, a message sent to this address will reach a user regardless of which of the central UNIX systems s/he happens to use. However Christa and Hopper will continue, at least for the foreseeable future, to use their own names when sending e-mail. This will allow users who are on off-campus e-mail lists to retain their current e-mail identity.

Local ListProc List Server Changes

For our local lists, i.e. lists with the address of 
            @lists.unh.edu
this distinction between central UNIX machines is no longer important. On Monday, 25-Aug-1997, all central UNIX subscriptions were changed, for all lists, to use the new cisunix.unh.edu address. This means that any subscriber with any one of the following machine addresses: 
            @kepler.unh.edu
            @christa.unh.edu
            @hopper.unh.edu
was automatically changed by our staff to: 
            @cisunix.unh.edu
At the same time, ListProc was updated to automatically translate any address seen coming from one of the above machines to its equivalent in the new format. In this way ListProc recognizes e-mail from any of the central UNIX machines as being equivalent. This should greatly reduce the problems we have seen in the past where people cannot post to a list or un-subscribe because they did not happen to send from the correct machine.

What this Means to You as a List Owner

For the most part, you only need to be aware that this address translation is taking place since it can be important when interpreting error messages from ListProc. Here's an example. Suppose that the user "wfc" sends a subscription request to the ListProc server for your list. In sending his subscription, say from Christa, he forgets that he is already subscribed to your list. ListProc will detect this and will automatically return the following (potentially confusing) message: 
      +-------------------------------------------------------------------
      |     From:  ListProc@lists.unh.edu
      |       To:  WFC@cisunix.unh.edu
      |  Subject:  Error Condition Re: Invalid request
      |
      |  >SUBSCRIBE YOUR.LIST Bill Costa
      |
      |  WFC@cisunix.unh.edu: You are already subscribed 
      |  to list Math.Teachers.Forum@lists.unh.edu
      |
As its first step in processing any request, ListProc automatically translates any address from Christa or Hopper to the new cisunix return address and then promptly forgets the original address. This is why ListProc error messages, like the one above, will show the new cisunix address, but not the user's original address.

This automatic translation also is done for new addresses added to your list. Thus if you should add the address 

            abc@christa.unh.edu
to your list, ListProc will automatically change (without comment) the address to 
            abc@cisunix.unh.edu
before recording the new subscription.

Notifying Your Subscribers

At the time the conversion was made, a message about these changes was sent to all subscribers with a central UNIX address. New subscribers since then, however, are not alerted in any way about this system. It is felt that this bit of e-mail magic behind the scenes will largely go unnoticed by all but a few individuals. Should you or one of your subscribers have a question or problem in regards to the automatic use of the cisunix with ListProc lists, please feel free to contact the server admin at: 
 
            List.Admin@unh.edu
A reply can generally be expected within the next two business days.