For delivery receipts forwarded by the SMPP Server, the stat sub-field value of short_message field may have one of the values defined in the following table.
|stat value||esm_class value||Description|
|ACCEPTD||0x20||The message has been accepted by the upstream carrier.|
|BUFFRED||0x20||The message is currently with the carrier and in pending status|
|NOCRED||0x4||Your SMS Central account has exceeded its credit limit (no credit).|
|DELETED||0x4||The message has been deleted at the carrier level and will not be delivered.|
|DELIVRD||0x4||Message was delivered.|
|ENROUTE||0x20||Message is en route, ie is still being routed to the mobile phone.|
|EXPIRED||0x4||Carrier has given up trying to deliver the message.|
|REJECTD||0x4||Carrier rejected the message.|
|SYSERR||0x4||An error has occurred at the carrier level and the message could not be delivered (system error).|
|UNDELIV||0x4||The message could not be delivered. The err sub-field should be consulted for further explanation - refer to Error Codes section for a detail on the sub-field.|
|FAILED||0x4||The message could not be delivered and has failed at the carrier level. The err sub-field should be consulted for further explanation - refer to Error Codes section for a detail on the sub-field.|
|UNKNOWN||0x4||The message has been sent to the carrier and is in an unknown state (no further information provided by the carrier). It is likely to not delivered.|
The esm_class value of 0x20 indicates that the delivery receipt is intermediate - a further receipt should follow.
The esm_class value of 0x4 indicates the delivery receipt is final.
The following table lists the possible err sub-field values which may be returned by the SMPP server in delivery receipts.
|0||Success; Message has been sent, delivery confirmation is pending|
|1||Success; Message has been successfully delivered|
|500||Failed; Internal SMS Central Server Error|
|503||Failed; Message has expired within the carrier|
|511||Rejected; Your username or password is incorrect|
|513||Rejected; Message rejected due to being a duplicate message|
|514||Rejected; No ‘RECIPIENT’ value was provided|
|519||Rejected; The number you tried sending to is blacklisted|
|531||Rejected; Your message contains no content|
|532||Rejected; Your message content has invalid characters. Please check your message text|
|534||Rejected; Credit limit exceeded. You have run out of SMS credit|
|535||Rejected: Your ‘ORIGINATOR’ value is not valid|
|536||Notice: Your message has been temporarily delayed|
|550||Failed: Message could not be delivered by carrier|