    # File lib/action_mailer/vendor/tmail-1.2.3/tmail/mail.rb, line 463
        def body=( str )
          # Sets the body of the email to a new (encoded) string.
          #
          # We also reparses the email if the body is ever reassigned, this is a performance hit, however when
          # you assign the body, you usually want to be able to make sure that you can access the attachments etc.
          #
          # Usage:
          #
          #  mail.body = "Hello, this is\nthe body text"
          #  # => "Hello, this is\nthe body"
          #  mail.body
          #  # => "Hello, this is\nthe body"
          @body_parsed = false
          parse_body(StringInput.new(str))
          parse_body
          @body_port.wopen {|f| f.write str }
          str
        end