Those settings are wrong.anybody having problems with recieving mail after changing settings? Mine was not working and found settings on the web that seems to have fixed it.
HSDPA settings:
Name: AT&T US HSDPA
APN: wap.cingular
proxy: <not set>
Port: <not set>
Username: WAP@CINGULARGRPS.COM
Password:CINGULAR1
Server:<not set>
MMSC: http://mmsc.cingular.com
MMS proxy: wireless.cingular.com
MMS port: 80
MCC:310
MNC:410
Authentication type: <not set>
APN type: default,supl,fota,dun
APN protocol IPv4
Can u please report back if it was a success?
sent for my atrix rocking Nottachtrix