I work a lot with application servers and virtual machines. While these are not mail servers they do need to be able to send out email for various reasons.

This post demonstrates how to install Postfix and Mailutils on Ubuntu.

Postfix

Installing postfix is quite easy.

sudo apt-get install postfix

Following along with the install wizard and keeping the defaults is generally fine.

Postfix Install Postfix Install

Mailutils

Following postfix I install mailutils

sudo apt-get install mailutils

With mailutils you can send out mail from the commandline with ease:

mail -s "Hello World" someone@example.com
Cc:
Hi Peter
How are you
I am fine
Good Bye
<Ctrl+D>

If you have trouble sending mail (perhaps you had another mail agent installed), then doing a reinstall might fix the problem.

service sendmail stop
sudo apt-get install --reinstall postfix