message_to_yaml.rb

# Годный метод для сериализации в yaml Mail::Message

class Mail::Message
  # @return [String]
  def to_yaml
    hash = {}
    hash['headers'] = {}
    header.fields.each do |field|
      hash['headers'][field.name] = field.value
    end
    hash['delivery_handler'] = delivery_handler.to_s if delivery_handler
    hash['transport_encoding'] = transport_encoding.to_s
    special_variables = [:@header, :@delivery_handler, :@transport_encoding]
    if multipart?
      hash['multipart_body'] = []
      body.parts.map { |part| hash['multipart_body'] << part.to_yaml }
      special_variables.push(:@body, :@text_part, :@html_part)
    end
    (instance_variables.map(&:to_sym) - special_variables).each do |var|
      hash[var.to_s] = instance_variable_get(var)
    end
    YAML.dump(hash)
  end
end