New custom HTML interface

[KrisR1]

Two things missing: 1 - view as webpage option 2 - Pre-header option. The rest is very nice. I like the live preview in page.

[Kyle_R]

Thank you for your feedback! Those would both be very nice additions. 

In the meantime, if you need to manually code a preheader you can add this code at the top of the body of your HTML and customize the text to your liking:

<div style="display:none; display:none !important; color:transparent; line-height:1px; max-height:0px; max-width:0px; opacity:0; overflow:hidden; visibility:hidden; height:0; width:0; mso-hide:all; font-size:0px;">This is a preheader</div>