Coming in a little late on this one but I hope some people see this and it helps. I am a web developer (among other things) and I want to share something related to the Gmail non-clickable links. The basics are really easy to understand if you look at it this way:

Some web servers (pending on the webmaster setup) will not allow access to certain web pages without the “www” being typed into search or browser. You may have noticed this in the past yourself. So therefore when going to a site it is usually a good habit to add the www or at least remember that if you get an error or a cannot be found message then try it with the “www” in the URL.

Now I cannot say that this is why Google has made this change but it certainly falls in line with their new functionality and an effort to making the net more universal to everyone.

So the LESSON from this webmaster is simple but yet important if you are sending out mass emails for marketing, etc. ALWAYS setup your links this way (whether using a word or graphic)
http://www.yourlinkhere.com or http://www.YourLinkHere.com
*THE KEY here is “USE THE ENTIRE PATH” including “www” and the “http://”. The Caps are not the issue, we are just seeing the results based on not using the “www” and a possible fix from Google. I will certainly not pretend to understand all of Google’s wisdom it is usually a mystery to most.

As you can see this will fall into all the rules needed to comply with all networks including Google’s new method and ANY other browser or ISP rules. It is a network thing so don’t bother yourself with the “why’s” just learn to do it the BEST way and you will never have issues with “Clickability” in your email campaigns. I hope this helps you.