Methods to Configure Exchange 2010 To Relay Email For An Additional Domain

Often companies have different internet domains or different subdomains. Employees may need to configure more than one subdomain on the same email client. This creates an issue is receiving emails as the Exchange Server can not differentiate between different subdomains. Since Exchange Server treats each organization server as a single SMTP account and relays emails according. If it is not able to find the username, a non-delivery report is sent to the sender. To configure Exchange 2010 To relay email for an additional domain additional steps needs to be performed. In this post, these steps have been described in detail to perform the configuration process.

What are the Different Types of Domain?

There are mainly three types of Domain that can be accepted by Exchange to relay messages. These are listed below:

• Authoritative Domain: This is the primary domain which is set up during the time the organization’s Exchange server is configured. This is the domain configured in the Setup Internet Address wizard asks for an email address. Then only one domain can be entered, which becomes the default address to relay emails. This is the authoritative domain. It is the only server responsible for sending or receiving emails. No subdomains are addressed under it. Additional settings are required to configure Exchange 2010 to relay email for an additional domain.
• Internal Relay: This kind of domain is used when some of the email addresses of an organization are not on Exchange. Some mailboxes are saved on an external server like a Google Mail server. Or there is more than one email ID under the same domain that needs to be properly addressed. The internal relay is used to route emails to the appropriate receiver. A Send Connector is used to relay messages of those email IDs that are not found on the domain.
• External Relay: This implies that all the mailboxes under a particular domain are saved on an external server. All the incoming emails need to be routed to some other server. Again, the send connector is set to Exchange to relay emails.

How to Configure Exchange Server for Multiple Authoritative Domains

An authoritative domain can be set using either Exchange Management Console or Exchange Management steps. Following are the steps to create a primary domain using the Exchange Administration Center.

Step 1: Create an Authoritative Domain

Before allowing multiple authoritative domains to receive emails through the Exchange server, users need to create a primary domain first. Here are the steps to create an authoritative domain.

• Firstly, login to the EAC, and go to Mail Flow >> Accepted Domains. Then, click Add+
• Now, fill in the Name field. This is the unique display name given to each organization
• Next, in the Accepted Domain text box, enter the SMTP namespace to which the organization accepts emails
• After that, choose Authoritative Domain
• Then, click Save.

Step 2: Setup an Email Address Policy

Following the creation of the primary domain, administrators need to configure an email address policy. This policy will allow more than one authoritative domain to reside on the Exchange server and relay emails. Users can either choose to remove an old primary email address or replace it for some recipients. Follow the steps below to perform this process.

Configure Exchange 2010 to Relay to External Email Addresses

To send an email to a mailbox saved on an external server, internal relay domain needs to be setup. When an accepted domain is configured as an internal relay domain, Exchange tries to deliver the message to the Exchange organization. If the domain in not found on the organization server, it relays the message to the SMTP connector.

Step 1: Create an Internal Relay Domain

Follow the steps below to use the Exchange Management Console to create an internal relay domain.

• From the console tree, Go to Organization Configuration >> Hub Transport. In the window click Accepted Domains tab
• Now, on this page type the organization name and SMTP namespace of the organization
• From this, select Internal Relay Domain
• Next, click New
• Next, click Finish to complete the process.

Step 2: Create a Send Connector to relay emails to shared namespace

Again, a send connector can be configured using the Exchange Management Console. Follow the steps below to configure a send connector through EAC.

• From the console tree, go to Organization Configuration >> Hub Transport. Click the Send Connectors Tab
• From this, click New Send Connector. This will start the send connector wizard
• Following this, type in the name field with the organization name. From intended use for this connector select an appropriate usage type. This determines the permissions for the send connector and grants permissions to the other server

1. Internal: For granting permissions to another Exchange server.
2. Internet: To grant permission to an external server like Google.

• Now, click Next
• Next, click Add and enter the domain name to which the send connector will relay the mail under SMTP Address Space. Tick the Include all subdomains check box if emails are to be routed to a subdomain of the address space. When finished click OK
• From the Network Settings section, choose Route mail through the following smart hosts and click Add
• Next, Add Smart Host dialog box will appear. From this, determine the IP Address of the smart host. Also, one can select the Fully qualified domain name (FQDN) of the smart host. When finished click OK. Repeat the process to add more than one smart hosts
• Next, select from different authentication methods like none, basic authentication, over TLS, Exchange server, external. Then click Next
• Now, click Add to add a source server. Then, determine the Hub Transport servers that will be a source server for sending and receiving messages. After that, click OK and then, Next
• Finally, review the summary and click Finish.

Wrapping It Up

Each and every company has its own list of branches and sections that have a separate list of subdomains. For example, sales branch has the email ids like ‘[email protected]’ and a marketing team has mailboxes with the name ‘[email protected]’. Often workers may have more than one mailboxes under different branches. Exchange only needs proper SMTP preferences to route emails accordingly. There are a lot of ways to configure Exchange 2010 to relay email for an additional domain. Some of them have been described in this post.