A common cause for non delivery in India is when the mobile number has been added to the National Do Not Call List (NDNC). As of February 1, 2009, new regulations were put in place by the Telecom Regulatory Authority of India. Any mobile number on this list is barred from receiving promotional, commercial, and other messages that they have not opted in to receive. For further information on the NDNC as well as instructions on how mobile users can have their number removed from the list, please refer to: http://ndncregistry.gov.in/ndncregistry/index.jsp
These regulations also affect the sender ID on messages sent to Indian networks as they will be altered and prefixed with TM if they are alphanumeric. Numeric sender IDs will be replaced by a local Indian number. Unfortunately, we have no choice but to adhere to these new regulations.