* Text: A standard 160 character text message. If you have long messaging enabled in the options section of your account you can send up to 612 characters.
* Unicode: A message that contains Unicode characters. The maximum length of a Unicode message is 70 characters and long messaging isn't supported for this.
* SmartMessage: A message that conforms to the Smart Message format. This type should be set when sending operator logos, ringtones, WAP Push messages, etc.
* Binary: Submit raw binary to the target handset. Used mainly to send messages to devices other than mobile phones. Operator logos, ringtones, etc. should be submitted as SmartMessage
