I have a couple questions around Email capability in Lightning:

1.  What's the difference among Email, Send an Email, and Send Email in the Salesforce1 & Lightning Actions on a Contact page layout?

2.  How do I add the "Email" tab to the Activity Composer?  I've included "Send an Email" in the Lightning Experience Actions of the Contact page layout, but it doesn't appear on the record.

Any assistance is greatly appreciated!