First, click on 'Email Setup' button

Once you have signed up for the Growth package this text box will allow you to HTML email code. 

Note: This feature is only available on our Please note that this feature is only available on our Pro, Premium and Enterprise plans. Feel free to contact support@postco.co for more information!

We have provided some sample code here to get you started

When using your own code all you need to do is add {{content}} into the HTML and this will pick up all text relating to the return and place it in the email. See sample below. 

Sample template email as you can see the specific text relating to the return displays where {{content}} is set.