Theses apn settings worked for My note
Name: ATT
APN: wap.cingular
Proxy: none
Port: none
Username and password are blank
Server: none
Mmsc:
http://mmsc.cingular.com
Mms proxy: wireless.cingular.com
Mms port: 80
Mcc: 310
Mnc: 410
Authentication type: none
APN type: Internet+mms