# File lib/mail/message.rb, line 1729
    def self.from_yaml(str)
      hash = YAML.load(str)
      m = Mail::Message.new(:headers => hash['headers'])
      hash.delete('headers')
      hash.each do |k,v|
        case
        when k == 'delivery_handler'
          begin
            m.delivery_handler = Object.const_get(v) unless v.blank?
          rescue NameError
          end
        when k == 'transport_encoding'
          m.transport_encoding(v)
        when k =~ /^@/
          m.instance_variable_set(k.to_sym, v)
        end
      end
      m
    end