Netherlands East Indies. (Postage Due). 1937. Air Mail envelope addressed to Sabang bearing Netherlands East Indies Air Mail SG 308, 10c purple and SG 345, 12 1/2c vermilion tied by Bandoeng date stamp '13/3/37' (Air Mail not valid) and taxed with 'T' hand-stamp and bearing Netherlands East Indies postage due SG D227, 2 1/2c salmon (block of four) tied by Sabang receiver '22nd Mars' and forwarded to Semarang bearing postage dues SG D227, 2 1/2c salmon (block of four) tied by Semarang '30th Mar' on reverse. Interesting item of taxed mail.