I dislike email HTML. There, I openly said it! I really had to get that out of my system before I go crazy.
It’s not perfect but it means something to me because I consider it to be the first real feature I’d developed and deployed to a live product with actual users.
While I thoroughly enjoyed the process of figuring out how to build a WYSIWYG (what you see is what you get) email campaign builder, I disliked the part where I had to figure out how to make it output HTML that would be compatible with over 70 email clients on multiple devices with different operating systems (surprise). Entire businesses have been built on how hard it is to get an email to look right on all devices.