Mountain Lion email share option opens a secondary Mail application I am having a weird issue when I use the share functionality baked into Mountain Lion. Whenever I have a file highlighted in finder and choose the email option to share a file with someone, it decides to "re-open" Mail. Now this is a problem for two reasons. One, having to start Mail up is an unnecessary waste of time if its already open (I always leave Mail running in a side space), and two, some of my accounts wont refresh because there are two simultaneous connections.

Here is a screenshot to better illustrate what is happening: 

I select the file, hit share and chose email.



A second Mail app opens and begins to launch displaying the compose box (with the file attached)



It is also visible twice in mission control:


As you can see, Mail is open and running twice. Does anyone know why this is happening? It would be nice to find a way to prevent it.
The most likely explanation for this is that you have at least two versions of Mail installed (for whatever reason). Your system default mail application happens to be the old version.

When an application uses the sharing API on ML to write an email, it is opened in the default system mail application. This setting, strangely enough, is inside Mail's preferences (not System Preferences).

Under the General tab is an item called Default mail reader, which is your system default.

In your preferred version of Mail, Open Mail -> About Mail, and note the version. Now select that version of Mail in Mail's preferences for Default email reader.