4. Planning and Configuring Your SMTP Namespace
Another important aspect is to plan and configure an SMTP
namespace. The SMTP message protocol is the internal message protocol
of Exchange 2010. Thus, you identify an Exchange organization by its
primary SMTP namespace.
The SMTP namespace is configured in the Internet using one DNS MX
record per SMTP domain that points to your Exchange organization. You
need to make sure Exchange understands what to do with the SMTP namespaces that enter your Exchange organization.
4.1. Accepted Domains
The accepted domain
property specifies one or more SMTP domain names for which the Exchange
server receives mail. If an SMTP Receive connector on the Exchange
Server 2010 Hub Transport server receives a message that is addressed
to a domain that is not on the accepted domain list, it rejects the
message and sends a relaying denied response.
When you create a new accepted domain, you have three options for the domain type you can create:
Select this option if every e-mail addresses for this domain name
exists in Active Directory (as mailbox, contact, and so on). If a
message is received that has a recipient
e-mail address that is not in the Active Directory, an NDR will be
created for that message. The Contoso scenario, where you only use
Exchange as the messaging system, is an example where you define all
domains as authoritative.
Internal Relay Domain
This option is to configure a shared address space with one or more
messaging systems. If the e-mail address does not exist in your Active
Directory, Exchange will forward the message using a Send connector.
You need at least one Send connector with the internal relay domain
configured as address space so that the Hub Transport servers will send
the message that are not found in your Exchange organization to the
correct target SMTP server. For example, you would use this option
during a migration in which your legacy messaging system and your new
messaging system share the same e-mail addresses.
External Relay Domain
Select this option to relay messages to an SMTP server outside of the
Exchange organization or the organization's network. An Edge Transport
server is responsible for routing the messages received to the target
SMTP server. Your organization is therefore responsible for the DNS MX
record of this company and forwards every message received to the
target server. It requires a Send connector from the Edge Transport
servers to the external relay domain's SMTP server that includes the external relay domain as address space.
Note: To configure accepted domains using the Exchange Management Shell, use the New-AcceptedDomain or Set-AcceptedDomain cmdlets. This allows you to easily create or modify many domains with a single operation.
4.2. Remote Domains
Remote domains define
SMTP domains that are external to your Exchange organization. You can
create remote domain entries to define the settings for message
transfer between the Exchange Server 2010 organization and domains
outside your AD DS forest.
When you create a remote
domain entry, you control the types of messages that are sent to that
domain. You can apply message-format policies and acceptable character
sets for the messages that are sent from your organization's users to
the remote domain as well as determine out-of-office message settings.
4.2.1. Out-of-Office Message Settings
The out-of-office message settings control the messages that are sent to recipients in the remote domain. The types of out-of-office
messages that are available in your organization depend on both the
Microsoft Office Outlook client version and the Exchange Server version
on which the user's mailbox is located.
message is set on the Outlook client but is sent by the Exchange
server. Exchange Server 2010 supports three out-of-office message
classifications: external, internal, and legacy, as shown in Figure 7.
Figure 7. Out-of-office settings for remote domains
4.2.2. Message Format Options Including Acceptable Character Sets
You can configure multiple message format options to specify message delivery and formatting
policies for the messages that are sent to recipients in the remote
domain. The first set of options on the Message Format tab apply
restrictions to the types of messages that can be sent to the remote
domain, how the sender's name displays to the recipient, and the column
width for message text. These options include:
Allow automatic replies.
Allow automatic forward.
Allow delivery reports.
Allow non-delivery reports.
Display sender's name on messages.
Use message text line-wrap at column.
4.2.3. Exchange Rich Text Format Settings
Use the Exchange rich-text format settings to determine whether e-mail messages from your organization to the remote domain are sent by using Exchange Rich Text Format (RTF). Remember that the Microsoft RTF format is not automatically supported by every LINUX or UNIX SMTP
server; thus if the recipients of messages from your organization
complain about weird attachments or missing attachments, you should try
to disable RTF for that domain.
4.2.4. Character Sets
The Characters Sets options
let you select a MIME character set and a non-MIME character set to use
when you send messages to a remote domain.
5. TargetAddress Routing
Another way to modify message routing is to add a SMTP address to the TargetAddress
attribute of a mail-enabled user account object or a contact object.
After the attribute is added, the object is available in the Global
Address List (GAL) and also can be addressed by using its primary SMTP
address. Messages sent to the object will be automatically forwarded to
the SMTP address defined in TargetAddress.
The first time I used this technology was back in the old Exchange 5.5 days, with an Exchange migration product called Quest Exchange Migration Wizard. This tool created one contact for every mailbox and used the TargetAddress attribute to forward messages to the target environment.
attribute is defined on a per-object level; thus you can define which
objects are redirected and which are not. You should consider the
following if you're planning to use TargetAddress routing in your environment:
You need to configure a Send connector that includes the target domain as address space.
share one address space, create an Internal Relay Domain for it. The
internal relay domain should be the primary SMTP address of the
objects. This is required to have users in both messaging systems
(source and target) be able to address the contacts or mailboxes in
both system by using their primary SMTP address.
You need to create one contact or mail-enabled user account per e-mail address to be capable of forwarding it. The TargetAddress attribute will include a dedicated SMTP address for the target messaging system.
Note: Remember that as soon as you mailbox-enable a user account, the TargetAddress attribute will be removed and any message forwarding will be stopped.