redmine/app/views/users/_mail_notifications.html.erb

<p>
<%= label_tag "user_mail_notification", l(:description_user_mail_notification), :class => "hidden-for-sighted" %>
<%= select_tag(
      'user[mail_notification]',
      options_for_select(
         user_mail_notification_options(@user), @user.mail_notification),
      :onchange => 'if (this.value == "selected") {$("#notified-projects").show();} else {$("#notified-projects").hide();}'
     ) %>
</p>
<%= content_tag 'fieldset', :id => 'notified-projects', :style => (@user.mail_notification == 'selected' ? '' : 'display:none;') do %>
  <legend><%= toggle_checkboxes_link("#notified-projects input[type=checkbox]") %><%=l(:label_project_plural)%></legend>
  <%= render_project_nested_lists(@user.projects) do |project|
        content_tag('label',
          check_box_tag(
            'user[notified_project_ids][]',
             project.id,
             @user.notified_projects_ids.include?(project.id),
             :id => nil
          ) + ' ' + h(project.name)
        )
      end %>
  <%= hidden_field_tag 'user[notified_project_ids][]', '' %>
  <p><em class="info"><%= l(:text_user_mail_option) %></em></p>
<% end %>

<%= fields_for :pref, @user.pref do |pref_fields| %>

<% if IssuePriority.default_or_middle and high_priority = IssuePriority.where(['position > ?', IssuePriority.default_or_middle.position]).first %>
<p>
  <%= pref_fields.check_box :notify_about_high_priority_issues %>
  <label for="pref_notify_about_high_priority_issues"><%= t(:label_user_mail_notify_about_high_priority_issues_html, prio: high_priority.name.downcase) %></label>
</p>
<% end %>
<p>
  <%= pref_fields.check_box :no_self_notified %>
  <label for="pref_no_self_notified"><%= l(:label_user_mail_no_self_notified) %></label>
</p>
<% end %>