type in your details and they will send you a text with the correct settings.
If that doesn't work try...
Go to your APN settings...
"Wireless & Networks"
"Access Point Names" or APN's
Tap the MMS setting and scroll to the bottom "APN Type"
Tap it and add this to the mms already there.
So you APN Type should say ... mms,default,supl
Save and exit.
Now in your APN's list you have a radio button to select MMS. Select it and reboot your phone.
Try sending an mms to someone you know has there phone switched on. As if it isn't you get a "Failed to Send" or "Queued For Sending" message.
Use a small file to test it as large files may not be allowed on your or their network.
I hope this works.