I think I read the answer to this somewhere already but I can't find it. In Lightning there are three ways that you can view an email while you're composing it. One is under activities on the record detail page. The next is on the toolbar and the last is a pop up. We'd like to set the default so that if we click on any of the "Send Email" buttons that it will go straight to the pop up. Right now we have to go through all of the steps explained in the release notes to get to the pop up. 

http://releasenotes.docs.salesforce.com/en-us/summer17/release-notes/rn_sales_productivity_email_pop_out.htm

If we're unable to go straight to the pop up is there a way to add an icon at the bottom of the compose email similar to the doc button that will allow us to use the pop up? 

Thank you in advance.