The Web has come a long way in the past 4 or 5 years. The widespread adoption of the HTML5 and CSS3 standards, along with the increasing power of mobile devices has meant that you can do an awful lot now which was not possible just a short time ago. Websites using jQuery plugins and AJAX facilities are now very common. 

Unfortunately, there has been one element of the web which has lagged behind in progress. That's the email client. Few people update their email software as often as their browser. The top 10 email clients at this time are:

1 Apple iPhone 27%
2 Gmail 17%
3 Apple iPad 12%
4 Outlook 9%
5 Apple Mail 8%
6 Google Android 7%
7 Outlook.com 5%
8 Yahoo! Mail 4%
9 Windows Live Mail 2%
10 AOL Mail 1%

(source: http://emailclientmarketshare.com )

With such a fragmented market and many people still using older email clients, it can be very difficult to create email campaigns that will work equally well on all platforms.

One thing our clients often ask for is videos embedded in emails. One would think that in 2015, there would be a simple way to do this. However the support for embedded video is still quite poor. Despite valiant attempts at creating HTML 5 methods for embedding video in email, this will only allow about 60% of your audience to see it.

The table below (taken from http://www.emailonacid.com)  shows the support for different email clients to view html5 embedded video