Configure Postmaster, Microsoft Exchange Recipient and NDR forwarding in Exchange Server 2007 and 2010

Postmaster for external messages
In Exchange 2007 and 2010 it is considered best practice to configure a postmaster address in the organization. It is also a requirement to set a postmaster for all SMTP domains according to RFC 2821:

The postmaster address is used to send system-generated messages and notifications.

To set the postmaster address use the following command:
Set-TransportConfig -ExternalPostmasterAddress <email address>

For example:
Set-TransportConfig -ExternalPostmasterAddress

Microsoft Exchange Recipient for internal messages
There is also another type of recipient configuration that you need to do if you want to be able to monitor NDRs. The Microsoft Exchange recipient is a special recipient object that can be compared to an internal postmaster. The HUB transport servers forwards internal NDRs to this recipient and not the the Postmaster.

To configure an recipient for the Microsoft Exchange recipient  use the following command:
Set-OrganizationConfig –MicrosoftExchangeRecipientReplyRecipient <String>

The String can be one of the following:

  • Distinguished name (DN)
  • Canonical name
  • GUID
  • Name
  • Display name
  • Alias
  • Exchange DN
  • Primary SMTP e-mail address

Note that if the MicrosoftExchangeRecipientReplyRecipient is not configured all messages sent to the Microsoft Exchange recipient will be discarded.

NDR forwarding
Sometimes you have the need to monitor the NDRs sent through the organization. To be able to do that you will have to configure the transport configuration to send a copy of the NDRs to a specific mailbox. Note that this affects the entire organization and not a single transport server.

Using the the GenerateCopyOfDSNFor parameter you can specify which DNS codes that will be forwarded. To save you some work, Microsoft has enabled monitoring for  the following DNSs:

  • 5.4.8
  • 5.4.6
  • 5.4.4
  • 5.2.4
  • 5.2.0
  • 5.1.4

To configure forwarding use the following command:
Set-TransportConfig -GenerateCopyOfDSNFor <DSN1, DSN2, DSN3, …>

Set-TransportConfig -GenerateCopyOfDSNFor 4.4.7,5.5.2,5.7.3

Note that the use of GenerateCopyOfDSNFor requires you to configure the Microsoft Exchange recipient and/or ExternalPostmasterAddress.