Email recipient not accepted by the server

I receive the error message every time I try to send an email to my wife @live.com and my daughter @ gmail.com. I am able to send emails to others  that use Hotmail.com, gmail.com, Verizon.net, Comcast.net with no problems. For my wife and daughter I just copy the message and logged on to my live account and they were sent with no problems.  

Hello,

What mail service provider are you using yourself?

I have the same problem - and using Google - Gsuite for Business
Any solution?