[Support] total received DLR and Submit response vs total sent SMS

Greetings.

I am trying to send text to more than 50,000 phone numbers at once (hopefully that doesn't cause a problem, right?). I am also not using `message ID` in my **submit_sm**, just to note if that also has an impact.

After the messages are sent, I have another nodejs process that only listens to delivery reports, at the end of the day when I check the total number of _delivered SMS + undelivered (or expired...) reports + failed to be sent_ **is not equal to a total phone number that I have tried to send text message**

1. Is there any accurate way to do this?
2. Does omitting message ID cause some problems?
3. I am receiving PDU command_status of 1375 on the failure report to send sms, is that a custom error code?

Thank you