Applies to: Exchange Server 2007 SP3, Exchange Server 2007 SP2, Exchange Server 2007 SP1, Exchange Server 2007
Topic Last Modified: 2007-08-20

This topic describes the configuration and management of the external postmaster address. The external postmaster address is used as the sender for system-generated messages and notifications that are sent to message senders that exist outside the Microsoft Exchange Server 2007 organization. An external sender is any sender that has an e-mail address that contains a domain that is not defined in the list of accepted domains for the Exchange 2007 organization.

Configuration of the external postmaster address is controlled by the ExternalPostmasterAddress parameter in the Set-TransportServer cmdlet on every computer running Exchange 2007 that has the Hub Transport server role or Edge Transport server role installed. By default, the value of the ExternalPostmasterAddress parameter on every Hub Transport server and Edge Transport server is set to the value $null. The value $null causes the following behavior on Hub Transport servers and Edge Transport servers in the Exchange organization:

Before You Begin

To perform the following procedures, the account you use must be delegated the following:

  • Exchange Organization Administrator role

To perform the following procedures on a computer that has the Edge Transport server role installed, you must log on by using an account that is a member of the local Administrators group on that computer.

For more information about permissions, delegating roles, and the rights that are required to administer Exchange 2007, see Permission Considerations.

Modifying the External Postmaster on Hub Transport Servers and Edge Transport Servers

For most Exchange organizations, the default value of the external postmaster address is correct. However, there are situations where you may have to modify the external postmaster address on a Transport server.

Note:
If you specify a custom value for the external postmaster address, that value is not replicated to any Edge Transport servers that are subscribed to the Exchange organization. If you specify a custom value for the external postmaster address, you must manually configure the external postmaster address on any Edge Transport servers.

Parameters that are configured by using the Set-TransportServer cmdlet only apply to the Hub Transport server or Edge Transport server on which the cmdlet is run.

To use the Exchange Management Shell to modify the external postmaster address on a single Hub Transport server or Edge Transport server

  • Run the following command:

    Copy Code 
    Set-TransportServer <TransportServerName> -ExternalPostmasterAddress <ExternalPostmasterSMTPAddress>

    For example, to set the external postmaster address to postmaster@contoso.com on the Transport server named Hub01, run the following command:

    Copy Code 
    Set-TransportServer Hub01 -ExternalPostmasterAddress postmaster@contoso.com

You can use pipelining in the Exchange Management Shell to modify the external postmaster address on all Hub Transport servers in the Exchange organization at the same time.

To use the Exchange Management Shell to modify the external postmaster address on all Hub Transport servers in the Exchange organization

  • Run the following command:

    Copy Code 
    Get-TransportServer | Set-TransportServer -ExternalPostmasterAddress <ExternalPostmasterSMTPAddress>

    For example, to set the external postmaster address to postmaster@contoso.com on all Hub Transport servers in the Exchange organization, run the following command:

    Copy Code 
    Get-TransportServer | Set-TransportServer -ExternalPostmasterAddress postmaster@contoso.com
Note:
You can't use pipelining to modify the external postmaster address on more than one Edge Transport server at the same time. You must modify the external postmaster address on each Edge Transport server separately.

Creating a Postmaster Recipient to Receive Messages That Are Sent to the Postmaster Address

By default, no mailbox or other recipient object is configured to receive messages that are sent to the postmaster e-mail address for any accepted domains that are defined in the Exchange organization. According to RFC 2822, each mail domain must have a defined postmaster address. To comply with this requirement, you may perform either of the following actions:

  • Create a new mailbox that is named "Postmaster". The default e-mail address policy of the Exchange organization should automatically add an SMTP address of postmaster@<Authoritative domain> to the mailbox.

  • Add the postmaster e-mail address to an existing mailbox.

For more information, see the following topics: