_connect.html.haml

%section.page-header.page-header-sm.parallax.parallax-3{:style => "background-image:url(#{asset_path 'background2.jpg'})"}
  .overlay.dark-2
  .container
    %h2.weight-300.text-white.wow.fadeInUp{"data-wow-delay" => "0.8s"} Connect with Silverlane
%section
  .container
    .row
      .col-md-3.col-sm-3
        %hr.margin-top-50/
        %p
          %span.block
            %strong
              %i.fa.fa-map-marker
              Address:
            %br/
            4600 South Syracuse St., Floor 9
            %br/
            Denver, CO 80237
          %span.block
            %strong
              %i.fa.fa-envelope
            = mail_to Setting.contact_email, "Send an email >>", encode: "hex"
          %span.block
            %strong
              %i.fa.fa-linkedin
            = link_to 'LinkedIn Profile', Setting.linkedin_url, target: '_blank'

        %hr/
      .col-md-9.col-sm-9
        %h4 Let us know the one thing that's holding your business back and we'll get back to you with some steps you can take right now.
        = simple_form_for @contact do |f|
          %fieldset
            .row
              .form-group
                .col-md-4
                  = f.input :name, :required => true
                .col-md-4
                  = f.input :email, :required => true
                .col-md-4
                  = f.input :phone
            .row
              .form-group
                .col-md-8
                  = f.input :subject
                .col-md-4
                  = f.input :interest, collection: Contact::Interest.all
            .row
              .form-group
                .col-md-12
                  = f.input :message, :as => :text, :required => true
                  .hidden
                    = f.input :nickname, :hint => 'Leave this field blank!'
            .row
              .col-md-12
                = f.button :submit, 'Send message', :class=> "btn btn-primary"

contact.rb

class Contact < MailForm::Base
  attribute :name,      :validate => true
  attribute :email,     :validate => /\A([\w\.%\+\-]+)@([\w\-]+\.)+([\w]{2,})\z/i
  attribute :phone
  attribute :subject
  attribute :interest
  attribute :message
  attribute :nickname,  :captcha  => true

  def headers
    {
      :subject => "Connect Message from Silverlane.io Site",
      :to => Setting.contact_email,
      :from => %("#{name}" <#{email}>)
    }
  end

  class Interest
    KEYS = [
      CONSULTING      = "Consulting",
      AUDITING        = "Auditing",
      MANAGEMENT      = "Management",
      TRANSFORMATION  = "Transformation",
      INTEGRATION     = "Integration",
      COLLABORATION   = "Collaboration",
      ANALYTICS       = "Analytics",
      SECURITY        = "Security",
      TALENT          = "Talent"
    ]

    def self.keys
      KEYS
    end

    def self.all
      keys.map { |key| new(key) }
    end

    def initialize(key)
      @key = key
    end

    # simple_form automatically uses `id` for the option value.
    def id
      @key
    end

    # simple_form automatically uses this for the option text.
    def name
      # I18n.t(@key, scope: :"models.order.interests")
      @key
    end
  end
end

contacts_controller.rb

class ContactsController < ApplicationController
  skip_before_action :authenticate_user!

  def new
    @contact = Contact.new
    @page_title = t('page_title.contact')
  end

  def create
    @contact = Contact.new(params[:contact])
    @contact.request = request
    if @contact.deliver
      flash[:notice] = t('contacts.delivery')
      redirect_to root_path
    else
      flash.now[:error] = t('contacts.error')
      render :new
    end
  end
end