# File lib/mail/message.rb, line 1277 def method_missing(name, *args, &block) #:nodoc: # Only take the structured fields, as we could take _anything_ really # as it could become an optional field... "but therin lies the dark side" field_name = underscoreize(name).chomp("=") if Mail::Field::KNOWN_FIELDS.include?(field_name) if args.empty? header[field_name] else header[field_name] = args.first end else super # otherwise pass it on end #:startdoc: end