Forwarding Email

R. Morrison
November 11, 1993

Email systems at the University of Wyoming have become more complex in recent months because multiple mail systems are now supported on multiple different computers. When a user has accounts on multiple computers, the user has a different mail address for each different computer. Also, the user must either read mail on each of these computers or forward all mail to a single computer.

A central mail gateway has been installed in order to simplify this situation. The central mail gateway allows each e-mail user at the University to have a single address and facilitates sending all of the user's mail to a single computer.

For example, suppose that John Doe has an account with the name JDoe on each of the following computers: Plains, Outlaw, Deputy and Horse (a Unix workstation). Since each of these systems have a mail system capable of sending or receiving mail, John could receive mail from any of these systems using the following email addresses:

JDoe@Plains.UWyo.Edu
JDoe@Outlaw.UWyo.Edu
JDoe@Deputy.UWyo.Edu
JDoe@Horse.UWyo.Edu

Suppose John wishes to read all of his mail on a single computer, say Deputy, and that he wishes to advertise a single email address regardless of where he reads his mail. Utilizing the central mail gateway, John could advertise a single mail address, JDoe@UWyo.Edu and could have all of his mail delivered to the computer of his choice. He could still send mail from each of the different computers and his outgoing mail would all have a return address of JDoe@UWyo.Edu regardless of the computer used to originate the mail .

In order to make this all work, the following would need to be done:

1) Set mail forwarding on each computer where John does not intend to read mail. This is necessary in the event a user on the same computer sends mail to JDoe instead of JDoe@UWyo.Edu. If John did not forward mail on this computer, the mail remain on the computer where it originated waiting for John to read it.

The following commands would be issued in the various mail systems in order to forward John's mail:

Outlaw - set redirect JDoe@UWyo.Edu@smtp
Plains - set forward IN%"""JDoe@UWyo.Edu"""
Horse - Insert "JDoe@UWyo.Edu" in John's ".forward" file

(Note that mail could be redirected to JDoe@Deputy.UWyo.Edu instead of JDoe@UWyo.Edu, however this is not recommended because if John later decides to start reading mail on Horse or if his account on Deputy is moved to another computer, he would need to modify the forwarding address on each computer.)

2) Create an entry on Roper to direct any mail sent to JDoe@UWyo.Edu to JDoe@Deputy.UWyo.Edu. Information Technology intends to develop software which will allow each user to modify his or her own information on Roper. Because user authentication is a difficult problem, this software will not be available in the immediate future. In the meantime, users should contact their assigned User Consultant who will arrange to have the appropriate entries made in the Roper database.

The mail would then be forwarded as shown in Figure 1. Note that all mail sent to @UWyo.Edu is first received by Roper and then redirected to the appropriate computer. If no entry exists on Roper for a given username, the mail is delivered to the default computer, Plains.

If John later decided to read his mail on Horse, the following steps would be required: 1) Remove mail forwarding on Horse. 2) Forward mail from Deputy to JDoe@UWyo.Edu. 3) Request that the Roper database be modified to redirect mail addressed to JDoe@UWyo.Edu to JDoe@Horse.UWyo.Edu.

Special arrangements are necessary in order for mail originating from a computer to have a return address of username@UWyo.Edu instead of username@computername.UWyo.Edu. Mail systems maintained by Information Technology are configured accordingly. Contact Postmaster@UWyo.Edu for more information.