a lot of people have been having a hard time getting MMS and WAP to work with the nokia 6600. however. a while ago tmobile upgraded their system and now it works. basically it is all the same except for the addition of a proxy server. so you can either add the proxy server info to your current config or you can add whole new connections using the correct info provided.

Proxy server info:
Primary Proxy Server Address: 216.155.165.050
Primary Proxy Port Number: 8080

The entire configuration is included here:
so here is the correct info:

Connection Name: T-Zones
Data Bearer: GPRS
Access Point Name: wap.voicestream.com
User name:
Prompt Password: NO
Password:
Authentication: Normal
Homepage: http://wap.myvoicestream.com
Connection security: off

Click on Options - Advanced Settings

Under advanced settings

Phone IP address: Automatic
Primary name server:
Second name server:
Proxy serv. address: 216.155.165.050
Proxy port number:8080

Connection Name: MMS
Data Bearer: GPRS
Access Point Name: wap.voicestream.com
User name:
Prompt Password: NO
Password:
Authentication: Normal
Homepage: http://216.165.155.84/servlets/mms
Connection security: off

Click on Options - Advanced Settings

Under advanced settings

Phone IP address: Automatic
Primary name server:
Second name server:
Proxy serv. address: 216.155.165.050
Proxy port number:8080