Sending email without postfix etc.

sudo apt-get install ssmtp
sudo apt-get install mailutils

Now edit the SSMTP configuration file

sudo nano /etc/ssmtp/ssmtp.conf

mailhub=smtp.gmail.com:587
hostname=raspberrypi
AuthUser=username@gmail.com
AuthPass=TheGmailPassword
FromLineOverride=YES
UseSTARTTLS=YES