How do I get iMessage to sync from iPhone to iPad and OS X Mountain Lion powered computer?
iMessage are present on all iDevices devices since iOS 5 update and now it has reached OS X Mountain Lion so you can now send and receive iMessage on your Mac. To use iMessage on Mac you should setup it using Apple ID, the same ID you use on iTunes, iCloud and other Apple services. It also allows to sync messages between iPhone, iPad and Mac but it doesn’t always work as intended, and some messages sent to the iPad won’t reach your Mac, and some messages sent to the Mac never reaches iPhone. If you find yourself in such situation here is what you can do about it:
On the iPhone and/or iPad:
Step 1) Go to “Settings” and then open “Messages” settings
Step 2) Scroll down and open “Receive At” which should be followed by a phone number or email address if setup properly.
Step 3) Now tap “Use your Apple ID for iMessage” and input your Apple ID and password
If you have more than one iOS device then repeat above steps on all your devices. Now you can close settings and take your Mac to continue setup.
On the Mac:
Step 1) From the Messages menu, select Messages, Preferences.
Step 2) Under the Accounts tab, select the desired account.
Step 3) Make sure the Apple ID used in Messages for OS X Mountain Lion is the same as the one used to setup iMessage in iOS.
From Apple related discussion boards I have noticed that this problem mostly affect users who set up iMessages on the iOS device a while ago using phone number as caller ID instead of Apple ID. Since Messages for OS X Mountain Lion uses an Apple ID instead phone number, the messages won’t sync between devices. This is the main reason why many OS X Mountain Lion complains about lost messages.
If you use several iOS and OS X devices, make sure you use Apple ID on all of them instead your phone number. This solution worked for my girlfriend’s iPhone and MacBook Air but I guess there could be some other problems with iMessage app. You can leave a message bellow with detailed description of your problem and we will do our best to solve it.