How to use MMS on T-Mobile iPhone 3G?

I have a factory unlocked iPhone 3G and I'm using T-Mobile, on my old phone I was abe to send and receive videos and pictures to and from others, but ever since i started using the iphone me and my friends were noticing none of my pics or hers went through to my phone, is there any way to use mms on iphone 3g? I don't have data plan and I'm usually in areas with Wi-Fi! Please Help!

Added (1). P.S. I did the thing where you change the settings on the cellular data network, and i got the info from t-mobile. NO LUCK

To setup T-Mobile Internet and picture messaging on your iPhone, follow these steps:

If you have access to Wi-Fi, start with Setup guide: Apple® iPhone®.
From the main menu, tap Settings.
Tap General.
Tap Network.
Note: For iOS6, tap on Cellular.
Verify the following settings:
Data Roaming: On
Wi-Fi: Off
3G Enable: Off
Note: The Apple® iPhone® is missing the WCDMA 1700/2100 band, and can't function on the T-Mobile 3G network until the network reallocation has been completed. See: T-Mobile Steps Up "Bring your own iPhone" Efforts.
Note: Changing the 3G Enable function while the device is on an active call may cause the call to disconnect.
Tap Cellular Data Network.
Configure the internet settings under the Cellular Data section:
APN: epc.tmobile.com
Note: For some iPhone unlocks you may need to use wap.voicestream.com.
Username: <Leave Blank>
Password: <Leave Blank>
Configure the picture message settings under the MMS section:
APN: epc.tmobile.com
Username: <Leave Blank>
Password: <Leave Blank>
MMSC: http://mms.msg.eng.t-mobile.com/mms/wapenc
MMS Proxy: 216.155.165.50:8080 (Leave Blank for 4S)
MMS Max Message Size: 1048576 (Leave Blank for 4S)
MMS UA Prof URL: http://www.apple.com/...uaprof.rdf
Press the Home button to save the APN and exit to the main screen.
Verify MMS is enabled:
Tap Settings.
Tap Messages.
Set MMS Messaging to On.
For iOS5 and lower, Tap MMS first.
Turn the device off and back on.
Test the connection by opening the Safari web browser and sending a picture message.