Hey,
What you are trying to do is use merged fields, this will retrieve a value from the table and place it into your email. To make Merged Fields work, you'll need to run a Character Function action for every table used in merge fields, specifically the 'Replace merge fields' command, to replace the merge fields with real values.
The character function action will need to go into the button that is sending the email. A screen you can look at for reference on how to do this, is the “New Activity” screen.
If you copy this screen and go down to the “send an email” section, edit the dropdown list for “Choose a template”. You will find an example of the action “Replace Merge Fields” here.
This should get you going in the right direction