Before you can use MMS you must set up your account.
There are 3 tabs and you must complete all the fields before you can use MMS.
Server:
Server: the URL of your mail server.
Gateway: the address of your wap gateway.
Send:
Expiry: how long the message should remain on the server before it is removed.
Visibility: if your address/phone number should be visible to the recipient.
Receive:
Allow delivery reports: if you want to allow a receipt to be sent indicating that you have viewed the message (if the sender has requested one). Keep in mind that you will be paying to send the receipt.