How does mail work in UNIX/BSD

I'm banging my head over this.

I'm going through 'Learning the bash shell' (which you may be familiar with) and am at the MAIL section of Shell variables in chapter 3. I'm trying to send a mail message with the mail command, but nothing happens. I've tried to send a message to my gmail account with

mail (email address) cntrl-d

to send, but nothing happens. Can someone tell me what I'm doing wrong/and tell me exactly what I'm supposed to do? Do I need to configure something, or what? I'm not sure this book is explaining things completely. All it does is talk about MAIL, MAIL PATH, and MAILCHECK; it's only a couple of pages.

HELP!

mail -s testing [email protected] < cameraString.txt

The less than sign uses the content in the file name that follows it. Without that, you just type in your message and use cntrl-d as you indicated.

Do a man mail

P.S. I'm using the tsch, but I don't think that matters here.

I did that and nothing happened. I get an EOT (what does that mean?)

Do I have to configure something?

I've looked at the man pages but the only thing it says about sending is cntrl-d, which I did.

Is there any book I can get about using the unix mail program?

I'm getting really frustrated with this

I don't know. I'm using Snow Leopard in case that might be a difference. I do not recall setting anything.

Perhaps a hint can be found at macosxhints.com

xstep --

I'm using Snow Leopard as well, but I get nothing.

What did you do to make yours work?

Besides the fact that I'm using the tcsh, I don't recall making any other changes or settings.