Disabling Message Sent Notification

The Message Sent Notification will appear after you sent out every SMS. You are not able to disable it in the Settings. The only way to disable the notification is to edit the registry.

Part 1: Disable Notification Sound

Go To: HKCU > Software > Microsoft > Inbox > MsgTypes > IPM > SMSText
Change: DLL Value to htmlnote.dll
Then: Soft reset.

Original DLL Value is mms.dll

The above part will disable the notification sound only.

If u want to disable the message sent notification also, follow the below steps

Part 2: Disable Message Sent Notification

Go To: HKLM > Software > Microsoft > Inbox > Settings

Change: MMSNoSentMsg name to SMSNoSentMsg
Change: SMSNoSentMsg value to 1
Then: Soft Reset

A Registry Editor like PHM or Resco Registry Editor is needed for this task.

Important Updates
It disable the SMS Program use by Samsung to achieve the objectives but it does not work on the newer ROMs and on WM 6.5 ROM. It only works on the older WM 6.1 ROM.You may want to use SMS-Chat Program if you want threaded messaging and no message sent notification.
SMS-CHAT Program>>>