The short answer is MAYBE.   If you are only using the component, then you will not have any issues using a "mailto" link within the information window for a marker.  However, if you use the mambot/plugin, you will potentially have problems.  The issue is that Joomla's base install contains an Email Cloaking mambot.  The Email Cloaking mambot will cause the Javascript code being written by the GMaps mambot to contain errors.  This will result in the map not being rendered properly.

Here are a couple of workarounds:

1. Turn the Email Cloaking mambot off temporarily until GMaps can be modified to support this
2. Put {emailcloak=off} inside the marker description.  That turns the email cloacking mambot off
   
3. Create a static page that contains the correct emails and have a link inside the information window with an href to that static page.
   

Hope this helps.