Problem : The capabilities of Exchange Server go beyond simply sending and
receiving email within a single domain, but also include the capability
to serve as an accepted domain that can send and receive emails for
additional domain namespaces. There are also concepts such as
authoritative domains and internal/external relay domains that require
both design and configuration know-how. How do these different concepts
work and how can you configure them on your transport servers?
Solution : To begin, what is the difference among all these different domain types?
How do they provide you great flexibility when configuring your
organization? The following are domain types:
Accepted domains—
If an Exchange organization is configured to send and receive email for
a particular SMTP namespace, it considers that an accepted domain. This
doesn’t necessarily mean that mailboxes are hosted within the
organization for that namespace. It could simply mean that email is
relayed through your organization. Authoritative domains—
These are accepted domains that officially host mailboxes for a domain
namespace. An Exchange organization can have more than one authoritative
domain. For example, if your company has two different products and
therefore two different namespaces, you can have persons send email to
users at either one, but your Exchange server will be able to determine,
by namespace, where that mail should go. When you first install
Exchange, you are given one authoritative, accepted domain configured on
your Hub Transport server. You are not provided an automatic accepted
domain on your Edge Transport server, however. Relay domains—
When a person sends an email that is by namespace designed to come to
your Exchange servers, if the email is not for an internal mailbox (in
other words, if the email was not sent to the authoritative domain), it
checks to see whether there is a relay domain it should send the email
toward. There are both external and internal ways to configure these
relay domains. On the external side, you configure your Edge Transport
server to relay over to the other domain’s Edge Transport server (if it
has one; if not, it can be the other domain’s Hub Transport). On the
internal side, you allow the message to come through the Edge Transport
server and then the Hub Transport server will relay it over to the other
domain’s Hub Transport server.
Note
Because an Edge
Transport server is a recommended role whereas a Hub Transport server is
mandatory, we perform most actions from the viewpoint of the Hub
Transport role. Performing the tasks on the Edge Transport is identical,
with the exception of having additional elements in the Exchange
Management Console to be visually concerned with.
Confirm the Domain Type
To quickly see (or alter) the type of domain you have configured on your transport server, perform the following:
1. | Open the Exchange Management Console (EMC).
| 2. | From the Navigation Tree, expand the Organization Configuration work center and click Hub Transport.
| 3. | From the Results pane, select the Accepted Domains tab.
| 4. | Select a domain (in most cases, you see only the first one created when you install the server).
| 5. | From the Actions pane, choose Properties.
| 6. | From the General tab (shown in Figure 1), you can see whether the domain is an accepted domain. You can also choose one of the following options:
- Authoritative Domain— Email is delivered to a recipient in this Exchange organization.
- Internal Relay Domain— Email is relayed to an email server in another Active Directory forest within the organization.
- External Relay Domain— Email is relayed to an email server outside this Exchange organization by the Edge Transport server.
| 7. | After you complete your check or make a change, click OK to return to the console.
|
Create a New Accepted Domain
Remember,
an accepted domain is one that allows inbound email routing. If you
need to create additional accepted domains, perform the following:
1. | Open the EMC.
| 2. | From
the Navigation Tree, expand the Organization Configuration work center
and click Hub Transport. (To create an accepted domain on an Edge
Transport server, within the console tree, from that computer, select
Edge Transport, and then within the Work pane, click the Accepted
Domains tab.)
| 3. | From the Actions pane, select the New Accepted Domain link to open the wizard.
| 4. | Provide a display name for the accepted domain.
| 5. | Provide the accepted domain SMTP namespace.
| 6. | Select the type of accepted domain you wish to create: Authoritative, Internal Relay, or External Relay.
| 7. | Click New.
| 8. | When the domain has been created, click Finish.
|
Note
Keep in mind that after
the accepted domain is created and configured, you still have to ensure
that the Domain Name System (DNS) for public email includes a mail
exchange resource record (MX) for the SMTP namespace that you just
included and that it points to the server IP address.
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