Adding E-mail Domain Used for Redirection to the List of Accepted Domains
To add a new Accepted domain, you can use either Exchange Admin Center or Exchange Management Shell.
To add a domain to Accepted Domains list using Exchange Admin Center
- In the Exchange Admin Center, navigate to Mail flow > Accepted domains, and then click Add +.
- In the Name field, specify the accepted domain, such as source.local.
- In the Accepted domain field, specify the SMTP namespace for which the Exchange organization will accept e-mail messages, such as *.source.local.
- Then select the Authoritative Domain. E-mail is delivered to a recipient in this Exchange organization option.
- Click Save.
To add a domain to Accepted Domains list using Exchange Management Shell
Run the following command:
new-AcceptedDomain -Name 'source.local' -DomainName '*.source.local' -DomainType 'Authoritative'
where *.source.local is the address space you want to use for mail redirection from the target to the source organization.
Configuring Source DNS Server for Mail Forwarding
After you have completed setting up the source Exchange 2016 organization for Internet mail flow between source and target Exchange organizations, you should also add the Mail Exchanger (MX) record for the source domain to the DNS server. This is necessary to forward the mail (redirected to the additional SMTP addresses added by the Directory Synchronization Agent) to the source Exchange server.
We will use the following additional address space given as example on the previous steps:
- @source.local—to redirect mail from target to source mailboxes. A secondary SMTP address will be added to each source mailbox by the Directory Synchronization Agent according to this template.
To set MX record for the source domain
- In the DNS snap-in, connect to the target DNS server and browse to the Forward Lookup Zones container.
- Right-click the Forward Lookup Zones and select New Zone
- In the New Zone wizard, select the Primary zone to be created.
- Type local for the Zone name and complete the wizard.
- Right-click the zone object local again, and click New Mail Exchanger on the shortcut menu.
- In the New Resource Record dialog box, type target for the Host or child domain.
- Click Browse and select the Exchange server in the source domain to which mail sent to the @source.local domain will be redirected.
- Click OK.
Testing the SMTP Connectors (Optional)
After both source and target Exchange organizations have been set up for Internet mail flow as well as both source and target DNS servers have been configured for mail forwarding, it is recommended to test the connection between the source and the target organizations.
Caution: This step should be performed in coordination with the administrator of the Exchange organization.
To test the SMTP connectors:
- Create test mailboxes on the source and target Exchange servers. In this example, both mailboxes will be called mbx1.
- Set the same primary SMTP address for both mailboxes.
- In this example the primary address for both mailboxes will be mbx1@Westland.Exchange.com.
- Set additional addresses for both mailboxes.
- In this example additional address for the source mailbox will be firstname.lastname@example.org, and email@example.com for the target mailbox.
- Create a contact on the source Exchange server and point it to the additional SMTP address of the target Exchange mailbox (firstname.lastname@example.org).
- Create a contact on the target Exchange server and point it to the additional SMTP address of the source mailbox (email@example.com).
- Open the test source mailbox and send a message to the source contact.
- Open the test target mailbox and make sure that the message has arrived.
- From the test target mailbox, send a message to the target contact, and make sure the e-mail has reached the source test mailbox.