Nokia 5230

Internet Settings:
Select Menu > Settings > Connectivity > Destinations > Internet > Options > New Access Point.
Tap on No > Packet data > Text field.
→ Enter good2go web and tap Green Check mark.
→ Tap OK.
Highlight good2go web and tap Options > Edit > Access Point Name.
→ Enter att.mvno and tap Green Check mark.
→ Tap OK.
Tap Homepage : http://ztdevice.home
→ Enter Homepage and tap Green Check mark.
Tap OK > Options > Advanced Settings > Proxy Server Address.
→ Enter proxy.mvno.att.ztarmobile.com  and tap Green Check mark.
Tap OK > Proxy Port Number.
→ Enter 80 and tap Green Check mark.
Tap OK > Back (until you reach the Main Menu Screen) > Internet icon > Web icon > Options > Settings > General > Access point > Internet > Options > Select Access point.
Highlight good2go web and tap OK.

MMS Settings:
Select Menu > Settings > Connectivity > Destinations > Multimedia Msg. > Options > New Access Point.
Tap on No > Packet data > Text field.
→ Enter good2go web and tap Green Check mark.
→ Tap OK.
Select New Access Point.
→ Highlight the new access point and then tap Options.
Tap on Edit > Access Point Name.
→ Enter att.mvno and tap Green Check mark.
Tap on OK > Homepage > Text field.
→ Enter good2go web .
Tap OK > Options > Advanced Settings > Proxy server address.
→ Enter proxy.mvno.att.ztarmobile.com and tap Green Check mark.
Tap OK > Proxy Port Number.
→ Enter 80 and tap Green Check mark.
Tap on OK > Back (until you reach the Main Menu Screen) > Messaging icon > Options > Settings > Multimedia Message > Access point > MMS > H2O Wireless.