I found the T-Mobile settings:
Instant Messaging
Instant messages are billed at the same rate as SMS. This includes using AIM, YIM, MSN Messanger and ICQ.
One method to save on SMS while still making use of AIM and YIM is to use either via WAP (will not work on pre-paid).
AIM can be accessed at
http://wimd.aol.com/?service=tmobileYIM can be accessed at
https://mm.yahoo.com/If you wish to use your phone's built-in IM client (and understand that each message will be billed as an SMS), the settings are as follows:
AIM:
GPRS Address:
http://wirelessvillage.t-mobile.comText msg. number: 4670
ICQ:
GPRS Address:
http://wirelessvillage.icq.t-mobile.comText msg. number: 4675
Yahoo:
GPRS Address:
http://wirelessvillage.yahoo.t-mobile.comText msg. number: 4700
MSN:
GPRS Address:
http://wirelessvillage.msn.t-mobile.comText msg. number: 4705
In the username and password fields, provide the phone with your actual username and password for each messaging service.
Found this on
http://wiki.howardforums.com/index.php/T-Mobile_Messaging#Instant_MessagingHere is a way to change the IM settings that SHOULD work:
Go to Admin Menu (*#6984125*#)
Tap Internals (type in master key (*#3818790*#))
Go to Protocol Settings.
Scroll down and tap IM Settings.
Tap on XML/WBXML
Check Show Server Settings.
Tap Save.
Exit out of the Internals and go to Messaging.
Tap IM.
Tap one of the Communities (AIM, MSN, Yahoo)
Tap More, then Settings.
Tap Server Settings.
Tap on the box under Server URL.
Delete everything and type in one of the GPRS addresses for the "Community" you selected.
Tap OK, then OK again.
Tap Save after the "Saved" pop-up appears and goes away.
Try logging in to AIM, MSN, Yahoo.
