To reach Jim Morrison on the system south.america.org, one would address the mail as jm@south.america.org. But if Jim's account was on a UUCP site named brazil, then his address would be brazil!jm. If it's possible (and one exists), try to use the Internet form of an address; bang paths can fail if an intermediate site in the path happens to be down. There is a growing trend for UUCP sites to register Internet domain names, to help alleviate the problem of path failures.
Another symbol that enters the fray is %—-it acts as an extra "routing" method. For example, if the UUCP site dream is connected to south.america.org, but doesn't have an Internet domain name of its own, a user debbie on dream can be reached by writing to the address not smallexample!
debbie%dream@south.america.org
The form is significant. This address says that the local system should first send the mail to south.america.org. There the address debbie%dream will turn into debbie@dream, which will hopefully be a valid address. Then south.america.org will handle getting the mail to the host dream, where it will be delivered locally to debbie.
All of the intricacies of email addressing methods are fully covered
in the book "!%@@:: A Directory of Electronic Mail Addressing and
Networks" published by O'Reilly and Associates, as part of their
Nutshell Handbook series. It is a must for any active email user.
Write to nuts@ora.com for ordering information.
Sending and Receiving Mail
We'll make one quick diversion from being OS-neuter here, to show you what it will look like to send and receive a mail message on a Unix system. Check with your system administrator for specific instructions related to mail at your site.
A person sending the author mail would probably do something like this:
% mail brendan@cs.widener.edu Subject: print job's stuck
I typed `print babe.gif' and it didn't work! Why??