76 Mail
so mail is delivered into /usr/spool/mail/alan (or whatever). So if you
really don’t want to learn how to read mail on a Unix, you have to
put a personal entry in the aliases file. I guess the .forward file in
your home directory is just a mechanism to make the behavior of the
Unix mailer more unpredictable.I wonder what it does if the file server that contains the aliases file is
down?Not Following Protocol
Every society has rules to prevent chaos and to promote the general wel-
fare. Just as a neighborhood of people sharing a street might be composed
of people who came from Europe, Africa, Asia, and South America, a
neighborhood of computers sharing a network cable often come from dis-
parate places and speak disparate languages. Just as those people who share
the street make up a common language for communication, the computers
are supposed to follow a common language, called a protocol, for commu-
nication.This strategy generally works until either a jerk moves onto the block or a
Unix machine is let onto the network. Neither the jerk nor Unix follows the
rules. Both turn over trash cans, play the stereo too loudly, make life miser-
able for everyone else, and attract wimpy sycophants who bolster their lack
of power by associating with the bully.We wish that we were exaggerating, but we’re not. There are published
protocols. You can look them up in the computer equivalent of city hall—
the RFCs. Then you can use Unix and verify lossage caused by Unix’s
unwillingness to follow protocol.For example, an antisocial and illegal behavior of sendmail is to send mail
to the wrong return address. Let’s say that you send a real letter via the U.S.
Postal Service that has your return address on it, but that you mailed it from
the mailbox down the street, or you gave it to a friend to mail for you. Let’s
suppose further that the recipient marks “Return to sender” on the letter.
An intelligent system would return the letter to the return address; an unin-
telligent system would return the letter to where it was mailed from, such
as to the mailbox down the street or to your friend.That system mimicking a moldy avocado is, of course, Unix, but the real
story is a little more complicated because you can ask your mail program to
do tasks you could never ask of your mailman. For example, when
responding to an electronic letter, you don’t have to mail the return enve-