That's a great question! I understand how important it is for your email to look exactly how you want it to be. However I can see you are still working in our older legacy newsletter. These templates only allow you to alter line spacing through the HTML coding of your block. With that said we are unable to offer support with altering your HTML. Instead we would suggest moving over to our Third Generation Editor. This newer version of our email templates do offer the option of controlling line spacing directly in the template.