New user with question on sms support

Just installed astersik version 1.6.4 with 3 sip extensions using x-lite softphone.

If I try to send a message from one x-lite extension (6002) to another x-lite extension (6001), I recieve a message that says it’s not supported.

The CLI however shows that extension (6002) is sending a simple message to extension (6001), It even prints the message out correctly. It then shows that the message was dropped.

Does Astrisk support sending sms from one in-house extension to another or do I need to add another application?