From the topic of this post it is safe to assume that I dislike HTML emails and I am fairly sure that I am not the only one. I am one of those people who are quite content with sitting back and reading my email in plain text via my favorite email client (which in my case happens to be mutt-ng).
I personally find receiving HTML email to be a bit on the annoying side as I should not have to resort to using auto-view to launch another application to view the message or hitting 'v' to see if they were nice enough to include an text plain attachment.
It is generally not to much of a hassle as most sites will give you the option of selecting one or the other when joining their newsletters and I can fix it right away.
However, I have been recently noticing an apparent increasing trend in using only HTML for simple order receipts and general communications from some of the various on-line storefronts and websites that I have frequented. This of course forces me to read through the code to figure out what the content of the message is.
One good example of this is Nintendo: I signed up for the Nintendo Power Monthly and Wii Newsletters and I have been getting a monthly emails that generally consist of an array of images that form the content of the message and a link.
I just wish more people would realize that not everyone wants to receive HTML email.