How to setup new domain in Office 365 to send email to users from 2 different old domains users

Occasional Contributor

We have a office 365 tenant and have a hybrid exchange environment with email addresses as .
All our mailboxes are in office 365 and the MX record are pointing to

We have another sub-organisation which has email addresses as
They have on premises exchange environment and use could based Secure Email Gateway as their MX record.

There is a requirement to setup a new verified domain in office 365 as in the tenant.
Users from both the domains will have email addresses as
Users from domain :-
- They will retain their old address and also have new address.
- Outbound mail Sender address will be address
Users from domain :-
- Do not need to be consumed in tenant in office 365 to avoid license use
- Inbound mail for users in sent to address
- Outbound mail for users in sent from address from their on-premises exchange

What is the best way to set this up?

1 Reply




How did you get on with this?


I'm thinking about doing something similar.