Exchange Server

EAC
(Exchange Admin Center)

Mail Flow > Send Connectors

[+] New send connector

new send connector

*Name:
Internet Mail

Type:
[x] Internet (For example, to send internet mail)

[next]

edit smart host

Specify a fully qualified domain name (FQDN), IPv4 address, or IPv6 address:
rsxxx.realsender.com

[save]

new send connector

*Network settings:
[x] Route mail through smart hosts
(unchanged)

[next]

new send connector - authentication

Smart host authentication:
[x] Basic authentication
[x] Offer basic authentication only after starting TLS

*User name:
(the one we sent you)

*Password:
(the one we sent you)

[next]

new send connector - routing

*Address space:

TYPE: SMTP
DOMAIN: *
COST: 1

[next]

new send connector - which exchange server

[EXCHANGE]

[add ->] EXCHANGE

[ok]

[finish]