Redirect to previous page OR embed login in restricted content message

Currently, we restrict content on our site to logged-in users. When a user is not logged in, they see the restricted access message with a link to the login page. We would like to have the ability for the end user to click a link in an email or external site, login, then be redirected back to the intended URL from the link. Alternatively, allow the login form to display in the restricted content message so they can stay on that same page for login, and the page will refresh once they have entered their credentials.