Hello Don, 

Just to update you about current EAI implementation, where it Should pass the domain name to the MTA (Mail Transport Agent) in Punycode. As of now with Oulook 2016 and  Gmail Web  in both cases ,we do not get punnycode domain name as probably suggested by this document, we get that full email address in unicode i.e अजय@डाटा.भारत

However XgenPlus MTA while receiving email is capable to receive Full Unicode & Unicode+Punnycode  email address. 

May be it requires re-alignment in view of whether the receiving MTA is advertising SMTPUTF8 or not, accordingly client might change its behavior.  

Note: (Gmail to Non EAI supporting server)
It may be worth noting here that if you send email from Gmail ID to unicode ID and the receiving MTA do not advertise SMTPUTF8 then Gmail returns email saying SMTPUTF8 not supported, and do not deliver email in punnycode. 

Looking forward to hear from everyone. 

Regards