Use the Delivery Route page under Settings > Hybrid Service > Hybrid Configuration to define the domains for which email traffic will be routed to and from the email hybrid service, and the SMTP server addresses that receive mail from and send mail to the hybrid service. Each group of one or more domains and one or more SMTP server addresses comprises a delivery route.
Important 
2.
Enter a Delivery route name.
3.
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Enter the Domain Address (for example, mydomain.com).
Note 
7.
To add inbound SMTP servers to your delivery route, click Add under SMTP Inbound Server Addresses.
To add more servers, click Add again. Each new server is given the next available ID number and added to the end of the list. The lowest ID number has the highest preference. Mail will always be received by the server with the highest preference; if that server fails, the server with the next highest preference for that delivery route is used.
9.
To add outbound SMTP servers to your delivery route, click Add under SMTP Outbound Server Addresses. The email system uses these IP addresses to send email to the hybrid service for encryption. See Advanced email encryption for information about this encryption function.
To add more servers, click Add again. Each new server is added to the end of the list. If an outbound server connection fails, email in this delivery route that needs to be encrypted is sent to a delayed messages queue for a later delivery attempt.
11.
Click Next to continue with hybrid configuration.