Ok, so sent messages from Messages app in 10.8.4 on Macbook do not show up in the app itself, even though people will receive them. They're also not showing on iPhone 5. Went through a de-activating and re-activating process, both on Macbook and iPhone via these steps: "1. Open Messages app 2. Go to preferences. 3. Sign out of the iMessage account. 4. Go to your iPhone, Sign Out of both iMessage and Facetime. Anything within the Message and Facetime section on the iPhone. TURN IT ALL OFF. 5. Restart the iPhone. 6. Turn on FaceTime & then turn on iMessage in your iPhone only. 7. Once the iPhone activates FaceTime & iMessage. You should receive a popup on your Mac. 8. The pop up will list the e-mails and not the phone number. No worries.. 9. Go into Messages preferences and log into the iMessage account. Once logged into Messages and the iMessages account, you should received 2 or 3 pop-ups that say the phone number was added to FaceTime and iMessage." The phone number registers and Messages on iPhone re-activates, but re-activating on Mac there was no pup-up (Messages on Mac already had the phone-number registered) and it still doesn't sync up and doesn't do anything for the messages not showing in Messages on OS X itself. Any ideas and/or solutions?