How to add the background color / highlight the Promo code in the preheader of HTML email on Gmail
I am working with a client who is interested in putting the promo code to be highlighted in the preheader text of email.
Please refer this screenshot => http://fuseedms.weareirissg.com/sample%20image.png.
I am not familiar with this method and was wondering if anyone can provide some insight on how to make this possible.
Are there a method recommended for this?