I have a Samsung phone and use T-Mobil phone service. I have suddenly started getting a notification beep when I sent a text to SOME people signaling text was delivered. It is just a few people where it happens when I text them.
It is annoying as hell.
Anybody else ever experience this and know how to stop it?
I know for sure that some of the contacts have Apple phones but unsure if that is part of the problem.

You are experiencing a feature, not a bug. The Android world has stated its intention to come into compliance with Apple's messaging infrastructure so as to make the texting between Apple and Android more "transparent." Delivery notification is part of that. As the various providers come into compliance, you will eventually get delivery notifications for messages sent to folks with Android phones as well as iPhones.

It should be configurable in your Settings/Preferences under Notifications, but maybe T-Mobile has not gotten around to that yet.

It tells me on the screen if it was delivered.
I sure don't care for annoyance of the audible notification.
I can't find any way to shut it off in my settings.
Maybe the next update will give me the otion.

You can shut it off in the settings I'm certain. it may be under Messaging or Notifications.

Still trying to stop it.
Latest update still doesn't give anyway to stop it.