Within a candidate's profile, you can send an email out from any workflow stage.
You can do this in one of two ways. One way is to click on the 'Email' icon on the upper right side of the candidate profile. this will open up the email draft page.
The other way to do this would be to click on the 'Messages' tab within the candidate profile on the left side of the page.
Then click on 'Send new message':
Finally, fill in the email as you wish with templates or free text on the pop up that appears.
You'll also be able to view all previously sent emails within the 'Messages' tab.