Are there any long code vs short code output restrictions?
Long codes are restricted by the carriers to 1 message per second (60 per minute) per originating phone number. This cannot be increased. Short codes can send up to 40 messages per second (2400 per minute). Duplicate messages sent within one minute will also be filtered, for both long codes and short codes. A “duplicate message” is defined as the same to, from and message body.