Received notice u/s 133(6) by post rather than through mail for the P.Y. 2011-12 regarding transaction through bank current A/c. While Assessee filed his 1st ITR in A.Y. 2014-15. Can transaction in current a/c justified when no ITR has been filed in that A.Y. by any means? Can A.O. sent notice by post only u/s 133(6)? How can we confirm the notice has been sent with prior approval of Additional/ Joint CIT?