Exchange 2016 Outbound Mail Flow.

After you install Exchange 2016, you may notice that there is no send connector. The setup process does not create a send connector for your environment. This is an issue if you plan on sending email outside your organization.

To set up a new send connector is a simple task that can be accomplished via the EAC or through the Exchange Management Shell. For a simple send connector to send all mail outbound to the internet the process is as follows:
In the EAC navigate to the send connectors page under mail flow. Then select the + to create a new send connector. Give the new connector a name. Choose one that is meaningful for it’s purpose. Since this connector will send all messages to the internet, choose Internet.
We don’t have a smart host so leave this as the default selection of MX record to utilize DNS to send outbound messages. To use this option, the server will need to have the ability to resolve external DNS records.
We want to ensure that messages to ANY domain are sent using this send connector so we need to add * as the domain for the address space.
Ensure that any servers you want to be responsible for sending mail externally are added to the new send connector.
Finish the wizard and you have now configured a send connector for the environment. If you have a firewall in your organization, you will need to ensure SMTP traffic is allowed outbound from any servers listed.

To accomplish the same thing using the Exchange Management Shell you can run the following command:

[PS] C:\Windows\system32>New-SendConnector -Name "OutboundSendConnector" -Internet -AddressSpaces "*" -SourceTransportServers EX16-1, EX16-2
With the above information, you should have a general understanding of how to create a basic send connector to get outbound mail flowing.