Here's some settings for the SPV C550 which work fine, perhaps worth a try !
Contract
1) Start>Settings>Data Connections>Menu>Edit Connections
Dialup connection:
Description: O2 CSD WAP
Connects to: The internet
Phone number: +447712927927
User name: o2web
Password: password
Domain: blank
Proxy connection:
Description: O2 WAP proxy
Connects from: The Internet
Connects to: Wap Network
Proxy(name

ort): 193.113.200.195:8080
Type: HTTP
Username:
Password:
GPRS Connection:
Description: O2 Internet
Connects to: The Internet
Access point: mobile.o2.co.uk
Username: o2web
Password: password
Primary DNS: 0.0.0.0
Secondary DNS: 0.0.0.0
I.P address: blank
GPRS connection:
Description: O2 GPRS WAP
Connects to: The internet
Access point: wap.o2.co.uk
Username: o2wap
Password: password
Primary DNS: 0.0.0.0
Secondary DNS: 0.0.0.0
I.P address: blank
GPRS connection:
Description: O2 MMS
Connects to: Secure WAP network
Access point: wap.o2.co.uk
Username: o2wap
Password: password
Primary DNS: 0.0.0.0
Secondary DNS: 0.0.0.0
I.P address: blank
In the main data connections menu.
Internet connection: O2 Internet
Work connection : Automatic
WAP connection: O2 GPRS WAP
Secure wap connection: O2 MMS
Start>Messaging>Media Messages>Menu>Options>Account Setup>Media Messages
Menu- Edit connections - Menu- Add
Server: O2 MMS
Download Messsages: automatically
Outgoing message size: less than 100kb
Allowed message types: personal
Menu>Edit connections
Description: O2 MMS
MMSC Address:
http://mmsc.mms.o2.co.uk:8002
Data Connection: Secure WAP network
Gateway: WAP 1.0 Gateway
I.P Address: 193.113.200.195
Port: 9201
In Internet explorer, Menu-Options-Connections
Untick 'automatically detect settings'
Make 'Select network: The Internet' or 'Select Network: WAP network'.
O2 PAYG
1) Start>Settings>Data Connections>Menu>Edit Connections
Dialup connection:
Description: O2 CSD WAP
Connects to: The internet
Phone number: +447712927927
User name: o2wap
Password: password
Domain: blank
Proxy connection:
Description: O2 WAP proxy
Connects from: The Internet
Connects to: Wap Network
Proxy(name

ort): 193.113.200.195:8080
Type: HTTP
Username:
Password:
GPRS Connection:
Description: O2 GPRS Wap
Connects to: The Internet
Access point: payandgo.o2.co.uk
Username: payandgo
Password: password
Primary DNS: 0.0.0.0
Secondary DNS: 0.0.0.0
I.P address: blank
GPRS connection:
Description: O2 MMS
Connects to: Secure WAP network
Access point: payandgo.o2.co.uk
Username: payandgo
Password: password
Primary DNS: 0.0.0.0
Secondary DNS: 0.0.0.0
I.P address: blank
In the main data connections menu.
Internet connection: O2 CSD WAP
Work connection : Automatic
WAP connection: O2 GPRS WAP
Secure wap connection: O2 MMS
Start>Messaging>Media Messages>Menu>Options>Account Setup>Media Messages
Menu- Edit connections - Menu- Add
Server: O2 MMS
Download Messsages: automatically
Outgoing message size: less than 100kb
Allowed message types: personal
Menu>Edit connections
Description: O2 MMS
MMSC Address:
http://mmsc.mms.o2.co.uk:8002
Data Connection: Secure WAP network
Gateway: WAP 1.0 Gateway
I.P Address: 193.113.200.195
Port: 9201
In Internet explorer, Menu-Options-Connections
Untick 'automatically detect settings'
Make 'Select network: Wap network' (for WAP over GPRS) or 'Select Network: The internet' (for WAP over CSD).
This was copied from another post.. but for the MMS part, u must go to Configurations which is among the menu such as settings, games etc.. right at the end ! and u'll find MMS settings.