See below pic adding a contact to serveradmin\ Companyname\ Exch2016_Base\ Hosted Organizations\ DomainName \ Contacts

works but when you pull up the new contact added in the Global Address Book on outlook or OWA and want to add that contact to your personal contact list the email is not test@test.com but test@DomainName.com,  in which the DomainName is equial to the company domain name you are hosting on Exchange 2016

and this is was it looks like when adding that contact to your personal contacts, it shows the email address associated with the domain you are hosting and not the domain you put in for the contact email.

Answered question