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.

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.

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:

  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:

  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:

  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:

  Get-TransportServer | Set-TransportServer -ExternalPostmasterAddress postmaster@contoso.com

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:

• How to Create a Mailbox for a New User
  
• How to Add a New E-Mail Address for a Mailbox User
  
• Managing Accepted Domains