app/views/door_mat/manage_email/new.html.erb
<h1>Add email</h1>
<%= form_for(@email, url: add_email_path) do |f| %>
<%= render 'door_mat/helpers/errors_if_any', {object: @email} %>
<div class="field">
<%= f.label :address %><br>
<%= f.text_field :address %>
</div>
<div class="actions">
<%= f.submit t("door_mat.manage_email.add_button") %>
</div>
<% end %>