First of all, please note that reports are only updated when we receive a confirmation from the handset*. In case the report shows delivered but you didn't get any message on your handset, there might be some setting changed from the handset due to which message get deliver on handset however the same is not getting reflected in mobile Inbox of end user. for e.g if any antivirus is downloaded in the handset has the features to block sms from Lm , Dm ,etc . These are basically the operator identifier and if any sms comes from LM-(sender id) operator will get the sms delivered to the destination mobile no. but handset get that sms rejected or spam. This is a handset dependent feature hence to fix the issue, kindly ask end user to put the sim card in another handset and do some testing or please arrange a live testing with us so that we can resolve the same.
Further request you to perform below standard troubleshooting.
• Check your device for failures, restart the device,
• Clear the device's memory of outdated messages,
• Check blacklists and spam filters of the device,
• Remove third-party software for working with sms, installed on the device,
• In case of Multi-SIM device, make sure that this sim card is active.
*For messages sent via operator route only. Not applicable for Modem Services.