app/views/devise/mailer/email_changed.html.erb
<p><%= t('.greeting', recipient: @email) %></p>
<% if @resource.try(:unconfirmed_email?) %>
<p><%= t('.message_unconfirmed', email: @resource.unconfirmed_email) %></p>
<% else %>
<p><%= t('.message', email: @resource.email) %></p>
<% end %>