A simple way that may work for a lot of people who just need basic output for their scripts or daemons to announce an action is this:
echo "body or message" | mail -s "realtechtalk.com" email@example.com
If you want to send a text file as the body just do this instead:
mail -s "realtechtalk.com" firstname.lastname@example.org < /tmp/sometxtfile.txt
These are some very basic but simple and powerful examples that could assist in basic shell scripting such as taking the output of a command and e-mailing it based on a cronjob etc..