Apple support is pathetic and rude. No proper customer support. Many developers are stuck or suffering on the same.

Hi there, Can someone please help me with my above query? My Legal entity name is Medinertia Technologies Pvt Ltd, and i bought a domain called medinertia.co.in and my emailid is support at medinertia.co.in. Still it says invalid email. Can someone help what domains it accepts? Is it just .com ?