The SMPP component can ask the server for the status of a previously sent SMS message with the CheckMessage function. The function will return a string containing either the date that the server reports as the message delivery date, or (in the case of an undelivered message) the current state of the message on the server. Possible message states are scheduled, unknown, en route, delivered (in which case the date of delivery will be returned by CheckMessage), expired, deleted, undeliverable, accepted or rejected. string msgchk = smpp.CheckMessage(MessageId);