I know this is a late response but I ran into the same problem and couldn't find a solution anywhere, however I ran across this post multiple times so I figured I'd post it here.
The problem arose for me when a link was emailed out without having http:// or https:// before the url.
So for example if I created a link:
<a href="www.something.com">Link</a>
On an apple computer it would show up as:
<a href="x-msg://201/www.something.com">Link</a>
which doesn't work.
The easy solution is to just add a protocol to the link:
<a href="http://www.something.com">Link</a>