Mandatory information about my setup:

Have I searched the tickets before posting? yes
Have I searched the forum before posting? yes
Have I read the documentation before posting (which pages?)? yes
Joomla! version: (unknown)
PHP version: (unknown)
MySQL version: (unknown)
Matukio version: (unknown)
Direct link to the page that shows the issue: (unknown) N/A


Description of my issue:

Whenever people sign up for a paid event, I want them to receive an email with a copy of their invoice sent automatically. How can I do that?