How to send emails on linux.

I use ubuntu system. How to find out which system you use, command is "uname -a".

I tried to send out email on ubuntu.

I tried on command line first.

I first installed postfix:

sudo apt-get install postfix

Then I tried the command:

echo "test message" | mailx -s "test subject" XXXX@xxx.com

And I got the following:

The program 'mailx' is currently not installed. You can install it by typing:

sudo apt-get install mailutils

So I installed mailx.

I got the message. 

And I put it in a linux shell script. Got it done.