the triggers for setting up this discount will be exactly the same as in the promo code tutorial.
you will just need to add one additional trigger:
Number of items with a specific column value
If the total number of items where 'discountable' has a value of '1' is '>' a value of '0'
then for the calculation use:
Based on items with a specific column value
Total of 'TotalPrice' where 'discountable' has a value of '1' 'times' '0.1'
substitute the percentage you wish to use. All of the available options for the discounts are explained in the eCart help docs. on the discounts tab, click the Help button to go to the context sensitive help page.
You can add universal Email after the checkout wizard has run, but it is simpler to do it within the checkout wizard. How to do it depends on the gateway and checkout method (Local or Remote) that you selected in the checkout wizard.