Setting up Hybrid Email setup with MS Exchange online and Third Party On-Prem (Non Microsoft)

Copper Contributor

I have a client with a third party mail server hosted on-premise. They are planning to have a hybrid setup where a part of the emails are to be hosted on Exchange Online and the remainder of the emails to remain on-premise with the third party. 

How can we implement such a scenario to ensure emails routing work properly. 
(New to this kind of hybrid setup)



1 Reply
The native Microsoft hybrid setup only works with Exchange servers.
You need to set up connectors in EXO to accept mail from the on-premises mail infrastructure and send mail to the on-premises mailboxes. You'll need to configure similar routing on the on-prem messaging infrastructure you are using.
The more difficult thing will be figuring out how the on-prem infrastructure identifies mailboxes that exist in EXO and routes mail for them to EXO (and the reverse in EXO). A native hybrid uses a combination of target addresses, mail enabled users and connectors to handle this. There might be some documentation the vendor has on how to achieve this.