The AutoAction is working great sending mail notifications for Posts, Comments, Likes, etc.
I thought I should share how I set it up if anyone else want's to do something similar.

This sends a mail using recipients username, and whoever initiated the activity's name. With a link to the Post.

<span style="font-size: 16pt;">Hi <b>[username]</b></br></span>
<span style="font-size: 14pt;"> There's been new activity in one of your groups from <b>[cb:userdata field="name" user="#me" /]</b>.</span><br /><span style="font-size: 22pt;"><b><a href="[cb:parse function="getContext" class="var2" /]" >Respond Here</a></b></span>