Applies to: Exchange Server 2007 SP3, Exchange Server
2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-06-20
A Foreign connector can only be installed on a computer that is running Microsoft Exchange Server 2007 and that has the Hub Transport server role installed. A Foreign connector uses a Drop directory to send messages to a local messaging server that does not use the Simple Mail Transfer Protocol (SMTP) as its primary transport mechanism.
Overview of Foreign Connectors
Exchange 2007 Hub Transport servers require Foreign connectors to deliver messages to foreign gateway servers that do not use SMTP to transmit messages. Third-party fax gateway servers are examples of foreign gateway servers. A Foreign connector controls outbound connections from the Hub Transport server to the foreign gateway server. The outbound messages are put in a Drop directory on the Hub Transport server or in a network file share on a remote server. Each Foreign connector uses its own Drop directory. The foreign gateway server must be configured to obtain messages from the Drop directory that is specified for that Foreign connector.
Foreign connectors that are created on Hub Transport servers are stored in the Active Directory directory service and are available to all Hub Transport servers in the organization. In Active Directory, a Foreign connector is created as an object in a connector's container. If there is a Foreign connector that is configured to send messages to an SMTP or non-SMTP address space, when any Hub Transport server in the organization routes messages to that address space, the message is delivered to a source Hub Transport server for that Foreign connector for relay to the destination domain. You can assign a Foreign connector to several different Hub Transport servers in your organization. This provides fault tolerance for the Foreign connector. If a Hub Transport server that contains the Foreign connector is unavailable, the messages that are destined for the Foreign connector's address space are relayed by using any of the other defined and available Hub Transport servers. To provide this fault tolerance, you must make sure that the Drop directory that is specified by the Foreign connector is available.
Foreign gateway servers can send messages into the Exchange 2007 organization by using the Replay directory that exists on the Hub Transport server. Correctly-formatted e-mail message files that you copy to the Replay directory are submitted for delivery.
For more information about the Replay directory, see Managing the Replay Directory.
Address Spaces and Connector Scope
The address space for a Foreign connector specifies the recipient domains to which the Foreign connector will route e-mail. You can specify SMTP address spaces or non-SMTP address spaces.
You can use the scope of a Foreign connector to control the visibility of the Foreign connector within the Exchange organization. By default, all Foreign connectors that you create are usable by all the Hub Transport servers in the Exchange organization. However, you can limit the scope of any Foreign connector so that it is only usable by other Hub Transport servers that exist in the same Active Directory site.
Address Spaces and Connector Scope in Exchange 2007 RTM
In the release to manufacturing (RTM) version of Exchange 2007, the complete syntax for specifying an address space is as follows:
The elements of the address space are described in the following list:
- ConnectorScope If you specify a value
Local, the connector can only be used by other Hub Transport servers in the same Active Directory site. If you omit the ConnectorScope qualifier, the connector can be used by all Hub Transport servers in the Exchange 2007 organization.
- AddressSpaceType The address space type
X400, or any other text string. If you omit the address space type, an SMTP address space type is assumed.
- AddressSpace For SMTP address space
types, the address space that you enter must be
RFC 1035-compliant. For example,
*.contoso.comare permitted, but
*contoso.comis not permitted. For X.400 address space types, the address space that you enter must be RFC 1685-compliant, such as o=MySite;p=MyOrg;a=adatum;c=us. For all other values of address type, you can enter any text for the address space.
- AddressSpaceCost The valid input range
for the cost is 1 to 100. A lower cost indicates a better route. If
you omit the address space cost, a cost of 1 is assumed. If you
enter a non-SMTP address space that contains the semicolon
character ( ; ), you must specify the address space
If you specify the connector scope, the address space
type, or the address space cost, you must enclose the address space
in double quotation marks (
" ). For
example, the following address space entries are equivalent:
You may specify multiple address spaces by separating
the address spaces with commas, as follows, for example:
contoso.com,fabrikam.com. If you specify the connector
scope, the address space type, or the address space cost, you must
enclose the address space in double quotation marks
" ) as follows, for example:
During routing resolution, a Foreign connector is selected to route e-mail for delivery to the destination domain. The Foreign connector that has the closest address space match to the recipient's e-mail address is selected.
Address Spaces and Connector Scope in Exchange 2007 SP1
In Microsoft Exchange Server 2007 Service Pack 1 (SP1), the address space syntax is slightly different from the address space syntax of Exchange 2007 RTM. In Exchange 2007 SP1, the complete syntax for specifying an address space is as follows:
The connector scope is specified by using the
IsScopedConnector parameter in the
New-ForeignConnector cmdlet or the
Set-ForeignConnector cmdlet. When the value of this
$False, the connector can be used by all
Hub Transport servers in the Exchange organization. When the value
of this parameter is
$True, the connector can only be
used by Hub Transport servers in the same Active Directory
All outbound messages that are sent to address spaces that are defined on a Foreign connector are put in the Foreign connector's specified Drop directory. Two items control the location of the Drop directory for each Foreign connector:
- The RootDropDirectoryPath parameter in the
Set-TransportServer cmdlet This option is used
for all Foreign connectors that exist on the Hub Transport server.
The value of the RootDropDirectoryPath parameter may be a
local path, or a Universal Naming Convention (UNC) path to a remote
- The DropDirectory parameter in the Set-ForeignConnector
cmdlet This value is set for each Foreign
Connector that exists on the Hub Transport server. The value of the
DropDirectory parameter may be a simple directory name or an
absolute file path. If the value of the
RootDropDirectoryPath is specified, the value of the
DropDirectory parameter must be a simple directory name. If
the value of the RootDropDirectoryPath is not specified, the
DropDirectory parameter may contain absolute path
information or may be a simple directory name.
By default, the value of the RootDropDirectoryPath parameter is blank. This indicates the value of RootDropDirectoryPath is the Exchange 2007 installation folder. The default Exchange 2007 installation folder is C:\Program Files\Microsoft\Exchange Server\. By default, the value of the DropDirectory parameter is the name of the Foreign connector. The Drop directory is not created for you. Therefore, you must manually create each Drop directory folder.
If the value of the DropDirectory parameter doesn't contain absolute path information, the location of the Drop directory is defined by the combination of the DropDirectory parameter and the RootDropDirectoryPath parameter. If the value of the DropDirectory parameter contains absolute path information, the value of the RootDropDirectoryPath must be unspecified. The location of the Drop directory is defined only by the value of the DropDirectory parameter.
Changing the location of the Drop directory does not copy any existing message files from the old Drop directory to the new Drop directory. The new Drop directory location is active almost immediately after the configuration change, but any existing message files are left in the old Drop directory.
The following permissions are required on the Drop directory:
- Administrator: Full Control
- System: Full Control
- Network Service: Read, Write, and Delete Subfolders and
You can specify the maximum allowed size for a Foreign connector's Drop directory by using the DropDirectoryQuota parameter in the Set-ForeignConnector cmdlet. When the specified maximum value is reached, no new message files can be copied into the Drop directory until the existing messages are delivered and deleted. By default, no maximum size limit is specified for a Foreign connector's Drop directory.
For more information, see How to Configure the Drop Directory of a Foreign Connector.
Relayed DSN Messages
When a message is sent with a delivery confirmation request to an address that is serviced by a Foreign connector, the sender should be notified if the recipient's messaging server cannot correctly process the delivery confirmation request. A Relayed delivery status notification (DSN) notifies the sender that the recipient's messaging system is unable to forward delivery confirmation requests. By default, Relayed DSN messages are not generated for messages that are sent to the address spaces that are serviced by a Foreign connector. DSN messages are defined in RFC 1894. For more information about DSN messages, see Managing Delivery Status Notifications.