The number of sites I visit that are responsive is growing. However, I just did a quick look through some of the HTML emails I have sitting in my inbox to see how many actually respond and fit nicely on my smaller screen. Most do not and they force me to scroll all over the place to actually see the content of their email. With more and more people reading their email on their phones and tablets, this is an area that can not be overlooked.
I have pulled out a few quotes from his article as he makes some very valid points about this topic.
HTML emails are a notoriously tricky medium for developers to work with. Archaic email client technology and a lack of standards have rendered many of the rules of modern, semantic code useless. But email is still a key marketing channel too important to be overlooked: over a six-month period in 2012, Litmus reported an 80% increase in email opens on mobile devices.
Take a visit over to his article if you are interested in this sort of thing.