The problem here is when we are sending back the message with session ID from the mBlox which is "AptyrB+v+LkAABkA+ncgAUaIPk807E800QQ$"... the SMSC return the error code... 0x00000435 (Vendor-specific error, please refer to your SMPP provider).. Using the Portal we have from MBlox we came to know that Session ID has not been delivered....
when i've got this error back from mblox in the past it's been due to attempting to use an alphanumeric sender id greater than 11 characters.
cheers iain
