Associate your mobile number with your Apple ID, if you haven't already done so.
Connecting Imessage To Macbook Pro
Sign out of iMessage on the Mac:
Set up iMessage. IMessage is the Apple messaging service you get automatically. Open iMessage on your Mac computer and go to Messages → Preferences. Click on Accounts and select your iMessage account. Turn on your phone number by selecting your Apple ID and clicking on the checkbox next to your phone number.
Messages▹ Preferences ▹ Accounts ▹ Sign out
and on the iPhone:
Connecting Imessage To Mac
Settings▹ Messages ▹ Send & Receive ▹ Apple ID ▹ Sign out
Then, on the phone, tap
Use Your Apple ID for iMessage
Turn On Imessage Mac
Sign back into iMessage on both devices and test. If there's no change, you may have to wait for a change in network conditions.
Credit for this solution to ASC user SmittyLove and to Glenn Fleishman of tidbits.com.
Aug 5, 2013 7:33 PM