XADM: NDR Sending Message to DL with Recently Deleted Mailbox

• Microsoft Exchange Server, versions 4.0, 5.0, 5.5

SYMPTOMS

When you send a message to a Microsoft Exchange Distribution List (DL), you may receive the following non-delivery report (NDR) for one or more recipients:

   Your message did not reach some or all of the intended recipients.

      Subject:   <Some subject>
      Sent:   <Date and Time>

   The following recipient(s) could not be reached:

      /o=<Organization>/ou=<Site>/cn=RECIPIENTS/cn=<Mailbox> on <Date and
    Time>

   The message was undeliverable because the recipient specified in the
   recipient postal address was not known at this address
               MSEXCH:MSExchangeMTA:<Site>:<Computer name>

CAUSE

This situation occurs when a user mailbox that was a member of the DL is deleted from the Exchange Server computer. All changes to objects such as mailboxes are updated in the transaction logs for the Microsoft Exchange directory and then later committed to the directory store (DIR.EDB) for fault tolerance. The Exchange message transfer agent (MTA) does not read the transaction logs, only the DIR.EDB, so the MTA must wait for the changes to be committed.

RESOLUTION

This problem will correct itself within a short period of time. On a large system, however, it may be desirable to run a Knowledge Consistency Check to speed up the process.