def remove keys
      keys = keys.map(&:to_sym)
      @options.reject! {|k, v| keys.include?(k) }
    end
def remove keys
      keys = keys.map(&:to_sym)
      @options.reject! {|k, v| keys.include?(k) }
    end
Remove an option.

 @example remove.
  require "pony-express"
  mail = PonyExpress::Mail.new
  mail.add to: "burns@plant.local", cc: "smithers@plant.local"
  mail.remove :cc