_form.html.erb

<!-- app/views/inquiries/_form.html.erb

<%= form_for inquiry do |f| %>
  <% if inquiry.errors.any? %>
    <ul>
      <% inquiry.errors.full_messages.each do |msg| %>
        <li><%= msg %></li>
      <% end %>
    </ul>
  <% end %>
  
  <div style="display: none;">
    <%= f.label :nickname %><br/>
    <%= f.text_field :nickname %>
  </div>
  
  <div>
    <%= f.label :name %><br/>
    <%= f.text_field :name %>
  </div>
  
  <div>
    <%= f.label :email %><br/>
    <%= f.text_field :email %>
  </div>
  
  <div>
    <%= f.label :message %><br/>
    <%= f.text_area :message %>
  </div>
  
  <div>
    <%= f.submit "Send" %>
  </div>
<% end %>

inquiry.rb

# app/models/inquiry.rb

class Inquiry
  extend ActiveModel::Naming
  include ActiveModel::Conversion
  include ActiveModel::Validations
  include ActionView::Helpers::TextHelper
  
  attr_accessor :name, :email, :message, :nickname
  
  validates :name, 
            :presence => true
  
  validates :email,
            :format => { :with => /\b[A-Z0-9._%a-z\-]+@(?:[A-Z0-9a-z\-]+\.)+[A-Za-z]{2,4}\z/ }
  
  validates :message,
            :length => { :minimum => 10, :maximum => 1000 }
            
  validates :nickname, 
            :format => { :with => /^$/ }
  
  def initialize(attributes = {})
    attributes.each do |name, value|
      send("#{name}=", value)
    end
  end
  
  def deliver
    return false unless valid?
    Pony.mail({
      :from => %("#{name}" <#{email}>),
      :reply_to => email,
      :subject => "Website inquiry",
      :body => message,
      :html_body => simple_format(message)
    })
  end
      
  def persisted?
    false
  end
end