Apologies if this has been asked elsewhere . . .
I have an HTC Radar on Tesco Mobile. Tesco can't help with this, and neither can HTC.
I can't send MMS messages. When I try, I get "unable to send".
Is there a setting I should change somewhere?
Using Connection Setup
The Connection Setup app makes it quick and easy to reconfigure your data connection settings.
When you change to another SIM card and restart your phone, Connection Setup opens and sets up your phone's data connection automatically based on your new SIM card.
If your mobile operator uses different profiles of connection settings for their data services (for example, different settings for Internet and WAP), you can also use this app to easily switch between their profiles.
Important: This app is preinstalled in most phones. If you don't see it on your phone, open the HTC Hub and download this free app.
Switching to another data connection profile
Manually choose a data connection profile in Connection Setup, if the app did not auto configure your phone's data connection, or if you need to switch to another profile of your mobile operator so you can use a certain data service.
On the Start screen, tap .
Tap Connection Setup.
Switch to another data connection profile of your mobile operator
Tap the Carrier field.
Select the profile you want to use.
Change to another country and mobile operator
Tap > manual select.
Select the country and mobile operator to use.
Tap to apply the changes.