anchor.diff:        <tr>
           <th>ID</th>
           <th>Sent at</th>
  +        <th>Action</th>
         </tr>
       </thead>
       <tbody>
  
positive.code:             <%= link_to(first_letter.id, letter_path(first_letter, style: first_letter.default_style), target: 'mail') %>
            </td>
            <td><%= first_letter.sent_at %></td>
          </tr>
        <% end %>
        <% @letters.each do |letter| %>
  
negative.code:             <%= link_to(letter.id, letter_path(letter, style: letter.default_style), target: 'mail') %>
            </td>
            <td><%= letter.sent_at %></td>
            <td>
              <%= link_to delete_letter_path(letter), :method => 'delete', data: { confirm: 'Are you sure you want to delete this email?' } do %>
                <span class="pull-right">
                  <i class="icon-remove-circle"></i>
                </span>
              <% end %>
            </td>
          </tr>
        <% end %>
      </tbody>
  