# File lib/sup/message.rb, line 330
  def quotable_header_lines
    ["From: #{@from.full_address}"] +
      (@to.empty? ? [] : ["To: " + @to.map { |p| p.full_address }.join(", ")]) +
      (@cc.empty? ? [] : ["Cc: " + @cc.map { |p| p.full_address }.join(", ")]) +
      (@bcc.empty? ? [] : ["Bcc: " + @bcc.map { |p| p.full_address }.join(", ")]) +
      ["Date: #{@date.rfc822}",
       "Subject: #{@subj}"]
  end