“You can’t use HTML5 or CSS3 in email.”
Due to their “limited” support, this is a commonly-held notion throughout the email design industry. However, we’re calling it a complete myth.
While support certainly isn’t universal, many of the leading email clients support HTML5 and CSS3. In fact, about 50% of the total market and 3 out of the top 5 email clients support them. Support may be even bigger for your particular audience.