UPDATED 6/28/10 with our fix in Cydia. Add the source: http://beta.leimobile.com/repo/ Install the MMS fix and reboot your iPhone. You may need to enter your APN after the reboot. The latest redsn0w (0.9.5b5-5) http://is.gd/buMgi should fix any APN/MMS issues. If you are already jailbroken just rerun this but deselect Cydia.
Many people have been asking for the MMS settings to use for T-Mobile. This will work on all versions of the iPhone and any firmware. Whenever you restore your iPhone you lose the settings and since T-Mobile is not an official carrier in the US yet, you will have to manually enter these settings in.
First you will need to navigate to: Settings->General->Network->Cellular Data Network and enter these settings: (IF YOU CANT EDIT, INSTALL ULTRASN0W FROM CYDIA)
APN: wap.voicestream.com
Username:
Password:
MMSC: 216.155.174.84/servlets/mms
MMS Proxy: 216.155.165.50:8080
MMS Max Message Size:
MMS UA Prof URL:
Once you are done just reboot your iPhone and MMS should be working. If they are not working correctly try these settings:
APN: epc.tmobile.com
Username:
Password:
MMSC: http://mms.msg.eng-t-mobile.com/mms/wapenc
MMS Proxy: 216.155.165.50:8080
MMS Max Message Size:
MMS UA Prof URL:
Reboot again and MMS should be working on your iPhone.
THESE SETTINGS SEEM TO WORK IF YOU HAVE JAILBROKEN YOUR IPHONE
Navigate to /var/mobile/Library/Preferences/com.apple.mms_override.plist on your iPhone and edit the file by pasting whats below. You can download a program like iEdit or ifile from cydia to do this.
PLEASE NOTE THAT THIS WEBSITE FORMATS THE QUOTATION MARKS WRONG. You will need to delete then and manually retype them. We will have a cydia file up soon where you will just have to download the file from cydia and be done.
You can download the file here until we get our cydia source up. Download
MMS
GroupModeEnabled
MMSC
http://mms.msg.eng.t-mobile.com/mms/wapenc
MaxMessageSize
1048576
MaxRecipients
10
MaxVideoBitrate
131072
Proxy
216.155.165.50:8080
UAProf
http://www.apple.com/mms/uaprof.rdf
UserAgent
SonyEricssonW800i/R1L
After that reboot your phone. Go and add epc.tmobile.com for the MMS apn and everything should work.