How do I add email sending capabilities?

[Gladfelder]

I have installed flexget which can send notification emails. syslog has the following error;

Terminal

Jan 31 19:15:23 xbian anacron[1026]: Job `cron.daily' terminated (mailing output)
Jan 31 19:15:23 xbian anacron[1026]: Can't find sendmail at /usr/sbin/sendmail, not mailing output

The folder, or any other containing 'mail', does not exist.

Please can someone give me NooB level instructions for adding this?[/quote]