Re: Why can't I send a message with an attachment on my AT&T Galaxy S3 using TMobile .
Sorry to take so long to get back to this...
Actually, the T-Mobile guy at 611 is probably wrong and the Samsung guy at Best Buy is probably wrong. Heck, I'm probably wrong. But I'm gonna give you my take on this situation anyway...
The tech support meatheads just tell everyone to do a factory reset. It's the cure for everything. Except it isn't. Most of the time it just keeps them from having to spend time on real troubleshooting. Chances are a reset was a waste of time, but it's done now.
How did you end up buying an AT&T phone from Best Buy but using it on T-Mobile? Did you pay full price for it and it came unlocked? Or did Best Buy unlock it for you? I'm just surprised you didn't buy AT&T service along with the phone.
Along with the above, did Best Buy know when you bought it that you were going to use it on T-Mobile? And if they knew, and since they now won't take it back, then aren't they responsible for selling you a phone they knew wouldn't work for you?
Anyway, like I said, the Samsung guy at Best Buy is probably wrong about AT&T phones on T-Mobile, they usually work fine. To check for yourself, you'll need to know the phone model and sub-model number. Then go to this site to find out if the phone will work:
http://www.willmyphonework.net/
Now, back to your text attachments. If you have internet access over WiFi they should be going through that way. Try sending a text without an attachment but with some emoji characters instead. I'd like to know if that works.
You never really said if you have working internet through T-Mobile. You said you have a data plan, and that you called 611, but not specifically if it actually works. I want to know if you can use it instead of WiFi to check email or go to websites. If it doesn't work at all let me know. If it does work then try as above, sending a text with emoji.
Android since v1.0. Linux user since 2001.