hi these are the newest settings im using they work completley for me mms sms web email everything
it is all case sensitive like user name password etc the mnc setting may vary if it doesnt work for you right away try 41 15 410 or 310 my area is north jersey its 41 or leave it default if there is one when you get the riht mnc you should see a small e with arrows next to you signal bar please change all these setings as my previous posts had typos also you need to have the http:// on mmsc url
name: AT&T
apn: wap.cingular
proxy blank
port blank
username:WAP@CINGULARGPRS.COM
password:CINGULAR1
server blank
mmsc:
http://mmsc.cingular.com
mms proxy: wireless.cingular.com
mms port: 80
mcc:310
mnc:41
apn type blank