Finally I found it. Here it is:
Operator Settings for Three Australia
(Only MMS at the moment)
Proxy Settings (Main Menu -> Connectivity -> Internet Settings)
Proxy Name: 3MMS
Proxy Address: 10.176.57.25
Access Point: 3services
Home:
http://mmsc.three.net.au:10021/mmsc
Port Number: 8799
Authentication Type: HTTP-BASIC
User Name: <<Blank>>
Password: <<Blank>>
Access Point Settings (Main Menu -> Connectivity -> Internet Settings)
Access Point Name: 3services
APN: 3services
Authentication Type: PAP
User Name: <<Blank>>
Password: <<Blank>>
DNS: <<Blank>>
Linger Time: 120
MMS Accounts (Main Menu -> Messaging -> Messaging Settings -> MMS Settings)
Profile Name: 3MMS
Proxy: 3MMS
Relay Server URL:
http://mmsc.three.net.au:10021/mmsc