I've just got myself a 2nd-hand unlocked Note Edge SM-N915K running Android 6.0.1 (Marshmallow). I am in Australia, but as it turns out this phone was originally from Korea. Not a big issue, but some things not set-up as expected.
I wanted to turn on delivery receipts for SMS, however the option isn't appearing in the menu (settings->application settings->messages->text messages). I already discovered that the developer menu is hidden by default, and found how to turn that on - thought it might be something similar with this option not appearing. Already spoke to someone at Samsung Australia, and ran through all the options, including resetting to factory defaults, but no luck.
Does anyone know hot to get this switched on? e.g. maybe a shell command or something, if not appearing in the menu as it should. I know delivery receipts are supported in Australia because I had it on my previous phone. Not sure about Korea (the Samsung person thinks it may be something to do with this, though I would've thought it was a fairly universal thing?). BTW when I discovered some of these issues, I did contact the place I bought it from for a possible exchange, but they said they had just sold the last one they had which was originally Australian (they had like half a dozen of them when I went in).