In Exchange Server 2007 the copy of NDRs is not enable by default. If you want to enable this please follow these procedures:
First of all, create an appropriate mailbox to receive the content, and also add the email@example.com to this mailbox
Set-OrganizationConfig -MicrosoftExchangeRecipientReplyRecipient "Postmaster Account"
Note: This is set up at Organization level
Set-TransportServer <Hub Server Name> -ExternalPostmasterAddress firstname.lastname@example.org
Note: We have to use this cmdlet for each Hub Transport server of the organization.
Choosing the NDRs that you want to receive
Okay, now we have a copy of the NDRs, but the question is.. which NDRs are we able to receive? By default the NDRs are: 5.4.8, 5.2.4, 5.4.6, 5.2.0, 5.4.4 and 5.1.4. But if you want to add or remove some NDRs you can accomplish this using the following cmdlet:
Set-TransportConfig -GenerateCopyOfDSNFor 5.4.X, 5.x.x>