Help Cannot send mms

[tongn]

1.) Model Number ? GT-S7500 (Samsung Galaxy Ace Plus)
2.) Firmware Version ? 2.3.6
3.) Baseband Version ? S7500ZSLE1
4.) Kernel Version ? 2.6.38.6 se.infra@SEI-47 #1
5.) Build Number ? Gingerbread.zsle1

T-mobile data plan: None
Country: US
SIM: Should be fine

Hi, sorry if this is the wrong place to post, but I am having problems sending mms with my new Galaxy Ace Plus. I have messed around with simple settings, but I'm not sure if any of the changes I've done could cause mms to fail to send.

Here's the information I believe will be useful:
1) I can receive mms (Had a friend mms me a photo)
2) Currently I am only using wi-fi for internet because I disabled "Use packet data" in mobile network settings (Tried sending mms with it on/off. I don't think it made a difference, could be wrong though)
3) I currently have 2 APN's (T-mobile US and TelKila - Selected by default)
4) Network mode - GSM/WCDMA (auto mode)

If anyone could provide some information as to how I can troubleshoot my problem it would greatly be appreciated.

 

[tongn]

I figure listing the APN's I have might be important.

T-mobile US:
Details can be found here - Support: Verify the Access Point Name (APN) and internet data connection - T-Mobile myTouch 3G / myTouch 3G Slide / myTouch 4G
I'm 99% sure the settings listed are the same settings I have on my phone.

TelKila:
I cannot do anything with this APN except select/deselect it. I am not able to open it to view the information like the T-mobile US APN.