For this, we will go to (EAC) Exchange Admin Center 2013, and login with a administrator user.
First of all, we go to MAIL FLOW where we can configure the receipt mail. Ensure that all yours domains are on the list ACCEPTED DOMAINS like in this picture
You can know your accepted domains with Exchange Managment Shell writing
To add a new accepted domain with Powershell you have this example.
New-AcceptedDomain –Name Domain2 –DomainName domain2.com –DomainType Authoritative
If you want to remove a Domain with powershell write:
When you finish with your Accepted Domain you need to configure the RECEIVE CONNECTORS. In this page you can see diferents connectors that your system use to receive mails. For example the first connector "Client Frontend" allow the anonymous traffic.
Here you can change the maximun receive message size, differents security parameters or the scope.
If you want to know your receive connector with PowerShell:
If you want more information write Get-Receive-Connector | fl
Now you have your acceted domains and your receive connector. You need to send mails, then you need to configure SEND CONNECTORS. By default, you dont have any connector, then we are going to configure one.
Add a new connector
Add a name and send the mails to Internet. With this configuration you send the mails to other people out of your company.
I dont have any smart host, then I select the MX record to send the mails to Internet.
Configure a new send connector.
If you want to know your send connector with powershell :
Get-Send Connector | fl if you want more information about your connectors