Delete old messages: Checkmark this setting to allow the phone to delete older messages in a thread when the Text message limit or Multimedia message limit is reached. Remove the checkmark to keep all of your messages.
Text message limit: Allows you to set the number of text messages to save per thread.
Multimedia message limit: Allows you to set the number of multimedia messages to save per thread.
Signature: Allows you to enter a signature to automatically send with your messages. Checkmark appears after a signature is entered.
Callback number: Checkmark to automatically add the callback number to your messages.