To monitor NDRs you have to configure your postmaster address in transport settings and organization config:
Set-TransportConfig –ExternalPostmasterAddress postmaster@domain.com
Set-OrganizationConfig –MicrosoftExchangeRecipientReplyRecipient postmaster@domain.com
Now you can set a transport rule for monitoring
Set-TransportConfig -GenerateCopyOfDSNFor “DSN-Number”
Example:
Set-TransportConfig -GenerateCopyOfDSNFor 5.1.0, 5.1.1
generates DSN Copys for the above DSNs.
Cheers, Chris