...Learning E-Mail (1 of 5) -- Send a letter to yourself

    The quickest way to start learning e-mail is to send yourself a
message.  Most public-access sites actually have several different types
of mail systems, all of which let you both send and receive mail. We'll
start with the simplest one, known, appropriately enough, as "mail," and
then look at a couple of other interfaces. At your host system's command
 prompt , type this:

             mail username

where username is the name you gave yourself when you first logged on.
Hit enter.  The computer might respond with

             subject:

     Type

             test

or, actually, anything at all (but you'll have to hit enter before you
get to the end of the screen). Hit enter.
     The cursor will drop down a line. You can now begin writing the
actual message. Type a sentence, again, anything at all.  And here's
where you hit your first Unix frustration, one that will bug you
repeatedly: you have to hit enter before you get to the very end of the
line.  Just like typewriters, many Unix programs have no word- wrapping.
     When done with your message, hit return. Now hit control-D (the
control and the D keys at the same time).  This is a Unix command that
tells the computer you're done writing and that it should close your
"envelope" and mail it off (you could also hit enter once and then, on a
blank line, type a period at the beginning of the line and hit enter
again).
     You've just sent your first e-mail message.  And because you're
sending mail to yourself, rather than to someone somewhere else on the
Net, your message has already arrived, as we'll see in a moment.
     If you had wanted, you could have even written your message on your
own computer and then  uploaded  it into this electronic "envelope."
There are a couple of good reasons to do this with long or involved
messages. One is that once you hit enter at the end of a line in "mail"
you can't readily fix any mistakes on that line (unless you use some
special commands to call up a Unix text processor.  Also, if you are
paying for access by the hour, uploading a prepared message can save you
money. Remember to save the document in  ASCII  or text format.
Uploading a document you've created in a word processor that uses special
formatting commands (which these days means many programs) will cause
strange effects.
     When you get that blank line after the subject line, upload the
message using the ASCII  protocol .  Or you can copy and paste the text,
if your software allows that. When done, hit control-D as above.