create_parts_from_responses

# File actionmailer/lib/action_mailer/base.rb, line 715
    def create_parts_from_responses(m, responses) #:nodoc:
      if responses.size == 1 && !m.has_attachments?
        responses[0].each { |k,v| m[k] = v }
      elsif responses.size > 1 && m.has_attachments?
        container = Mail::Part.new
        container.content_type = "multipart/alternative"
        responses.each { |r| insert_part(container, r, m.charset) }
        m.add_part(container)
      else
        responses.each { |r| insert_part(m, r, m.charset) }
      end
    end