It sounds like he is using your email address to contact you at your email address.
You need to associate only one of the email addresses on the iPad for the contact (send and receive) email address. Use your email address on the MacBook and have him use his own email address on the iPad, if it is verified.
Settings>FaceTime>You can be reached by FaceTime at:>His email address. Uncheck you email address in the settings on the iPad.
You should be able to associate multiple email addresses with one Apple ID for the purposes of FaceTime and Messages. I have 4 different email addresses and 1 iPhone number asscocuetd with my ID and they all work.
I thought you said that his email address was verified by Apple in your first post. Take a look at this and see if it helps. I apologize if you have already tried this and it isn't working, but I want to make sure.
Think I may have Facetime outgoing working with everyone, but me. Not sure if it has anything to do with the linked e-mails to one ID. Will keep working on it. At least I was able to connect to my daughter earlier and have tried since to send to both daughters with no answer cause they are at work, but did not get the unavailable message like before. That only happens with me. Will keep trying to figure that one out even if it means a trip to the Apple store sometime down the road. Thanks for the suggestions.
Using FaceTime http://support.apple.com/kb/ht4319
Troubleshooting FaceTime http://support.apple.com/kb/TS3367
The Complete Guide to FaceTime + iMessage: Setup, Use, and Troubleshooting
Troubleshooting FaceTime and iMessage activation
iOS: FaceTime is 'Unable to verify email because it is in use'
Using FaceTime and iMessage behind a firewall
iOS: About Messages
Set up iMessage
iOS 6 and OS X Mountain Lion: Link your phone number and Apple ID for use with FaceTime and iMessage
How to Set Up & Use iMessage on iPhone, iPad, & iPod touch with iOS
Troubleshooting iMessage Issues: Some Useful Tips You Should Try
Setting Up Multiple iOS Devices for iMessage and Facetime
FaceTime and iMessage not accepting Apple ID password
Unable to use FaceTime and iMessage with my apple ID
How to Block Someone on FaceTime
My Facetime Doesn't Ring
To send messages to non-Apple devices, check out the TextFree app https://itunes.apple.com/us/app/text-free-textfree-sms-real/id399355755?mt=8
How to Send SMS from iPad
You can check the status of the FaceTime/iMessage servers at this link.
Thank you for all of the suggestions. I'm not sure what changed because I didn't do anything different except going back into my contacts and connecting from there rather than my favorites and it works except for connecting with my Mac. I cleared my favorites and then reentered them after making the connections through the contacts list and all is good. I will maybe check with the Apple Store at a later date to see if we can figure out the connection to my Mac. Till then all is good Thanks for the help.
I know this is an old post but if anyone has this problem in the future. The exact same thing was happening to me. I was able to receive calls into facetime on my computer but couldn't make them. Every time I dialed out to anyone I got the message that the other party wasn't available. After checking all my settings I finally discovered that my region setting wasn't set to the United States. Once I changed it I was able to make calls out again. Hope this helps if anyone else experiences the same.