Another BYOP, Another MMS Problem

[hexe]

Been a ST customer for AT LEAST 10 years, went from a Motorola Kingfisher to a Galaxy SIII, happy camper all along. So...I bought an unlocked, BRAND NEW NEVER ACTIVATED ON ANY CARRIER, AT&T Galaxy Note 4 running Android Marshmallow 6.0.1, and a ST SIM card for said phone. Put the SIM card in, had my phone number ported to the Note 4.

First problem I ran into was not being able to set up my voice mail. After 2 weeks of phone calls & web chats, ST sends me a new SIM card to start over.
New SIM card solves voice mail problem. Hooray!

But--can't send or receive MMS texts, and can't access the Internet unless I'm on WiFi. Scour the ST pages, try the APN settings. No joy. Scour the Interwebs, try more APN settings, finally give up on using Samsung Message and download Textra app instead. Now I can receive MMS messages, and connect to the 'Net using mobile data. Yay!!

But--still can't SEND MMS texts. Scour the ST pages and forums, no help. Scour the Interwebs, try other APN settings, still can't send MMS. Boo!

Yes, I know: "Please note that updating your APN settings does not guarantee MMS (Multimedia/Picture Messaging) will work. MMS is dependent upon your phone model's limitations."

But this AT&T Galaxy Note 4 running Android Marshmallow 6.0.1 with all of the most recent updates/patches, is most definitely NOT limited to not being able to send MMS.

Suggestions, anyone? I'd just like to be able to use my freakin' phone and it's features.

[ST - Felice]

Hi Hexe. My name is Straight Talk Felice. We sincerely apologize about your issue with the MMS. Let us get your issue resolved. Please check your Forum inbox for assistance. For your convenience, our representatives are available Monday-Sunday from 8:00 AM to 11:45 PM EST. You may also text the key word HELP to 611611 to view our self-service menu with a list of help key words with valuable information.

[hexe]

Hmm. Just checked my Inbox, and there's nothing in there.

[ST - Felice]

Hi Hexe. Please re-check your Forum inbox for a message.