If you have previously configured an Authoritative Domain or Internal Domain, then you may want to automatically create email addresses for existing or new contacts. We often use the Company section under the Organization tab and enter the domain name that this user belongs to. The only thing to note here is that if you write a non-standard email address, you will have to edit the email address policy. Before it is applied, users will not be able to enter any criteria here. Until you finish (policies do not remove email addresses), it will only add extra addresses.
You will then have to configure an e-mail address policy. To do this, go to the Exchange Management Console and navigate to Organization Configuration > Hub transport and in the Action pane on the right, select New e-mail address policy . It will open a wizard to create a new policy.
Name the policy. As mentioned, it doesn't matter what your name is, but make sure you can identify the name of the policy when you need it later. Next, click Next .
On the Conditions screen, you will have to specify the criteria for the new policy recipient. If you want this policy to apply to all recipients, you should not do anything here. If you are creating a policy for the company, you can check ' Recipients is in a Company '. Click Next .
On the E-Mail Addresses screen , you need to specify which email address will be used by this domain. Choose one of the default settings (if no settings match the requirements, you can edit it later), then click the Browse button to select the domain you created earlier as an accepted domain. . Note that if this domain is not listed, Exchange may not have considered it as an accepted domain. Once you have selected the domain, click OK . Once you have returned to the main wizard screen, right-click the email address and it will help you edit the format of the address, allowing you to add a separate section for the address.
On the Schedule screen, select when you want to run the calendar. This process does not stop any services but if you have a large number of users, it will take a while to apply and potentially cause service errors. Click Next .
Check the details on the confirmation screen and if all is correct, click New . If there are any changes, click Back .
The final page of the wizard will confirm that the Exchange Management Shell command has been run and will notify if the policy creation and application to the recipient were successful. Click Finish to complete the Wizard.
The last part is DNS configuration. Users will have to configure the MX record for the new domain to use a record that meets the requirements of the rDNS record (PTR). This is the only thing to change. Since the Exchange server will connect to the recipient's SMTP services using the same IP address, no matter which domain you are using, you only need a rDNS record.