Exceptions: InvalidNumber, Failure
+deleteContact(number<s>) -> <>::
+* number : Phone number
+
+Exceptions: Failure
+
+deleteRecipient(number<s>) -> <>::
+* number : Phone number
+
+Exceptions: Failure
+
setExpirationTimer(number<s>, expiration<i>) -> <>::
* number : Phone number of recipient
* expiration : int32 for the number of seconds before messages to this recipient disappear. Set to 0 to disable expiration.