XCON: Intersite Message Transfer Agent Distribution List Cache Issue (229728)

SYMPTOMS

Distribution List (DL) membership may not be updated correctly across Exchange Server sites. In other words, after a DL member's mailbox had been deleted (at Site A, for example), other sites in the Exchange Server organization should not see the mailbox in the global address list. However, the remote sites may not be notified of the change to the DL membership. When sending to this DL from one of these remote sites (for example, Site B), a non-delivery report (NDR) may be generated by the message transfer agent (MTA) similar to the following:

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

Subject: Test MTA DL Cache message
Sent: 2/1/99 9:25 AM

The following recipient(s) could not be reached:

c=US;a= ;p=ORG;o=SITE;dda:MSXCHNGE=
//o=ORG//ou=SITE//cn=RECIPIENTS//cn=Deleted user; on 2/1/99 9:25 AM
The recipient name is not recognized
MSEXCH:MSExchangeMTA:SITE:SERVER

CAUSE

The MTA checks the "When Changed" attribute of the DL for updates before every expansion pass. Implicit deletion of the mailbox (that is, deleting it from a server, but not from the DL) does not update the "When Changed" attribute of the DL, even though the mailbox is no longer a member of the DL. The MTA still recognizes the mailbox is as a member of the DL because the MTA DL cache does not get updated when a mailbox is deleted, but not manually removed, from the DL. As such, the Site B MTA DL cache information is not updated because of the implicit deletion of the mailbox in Site A. Therefore, the Site B MTA continues to include the deleted mailbox when sending to the DL. Therefore, the Site A MTA continues to generate an NDR for the deleted mailbox.

RESOLUTION

A supported fix is now available from Microsoft, but it is only intended to correct the problem that is described in this article. Apply it only to computers that are experiencing this specific problem. This fix may receive additional testing. Therefore, if you are not severely affected by this problem, Microsoft recommends that you wait for the next Microsoft Exchange Server 5.5 service pack that contains this hotfix.

To resolve this problem immediately, contact Microsoft Product Support Services to obtain the fix. For a complete list of Microsoft Product Support Services phone numbers and information about support costs, visit the following Microsoft Web site:

http://support.microsoft.com/default.aspx?scid=fh;EN-US;CNTACTMS

NOTE: In special cases, charges that are ordinarily incurred for support calls may be canceled if a Microsoft Support Professional determines that a specific update will resolve your problem. The typical support costs will apply to additional support questions and issues that do not qualify for the specific update in question.

The English language version of this feature should have the following file attributes or later:

Component: MTA

File name	Version
Emsmta.exe	5.5.2564.0

MORE INFORMATION

After you apply the fix, the NDR may still occur if someone sends a message to the DL within 10 minutes of the mailbox being deleted, but after the 10-minute period, the NDRs will not occur for the deleted mailbox.

For additional information about this problem as it applies to intrasite DL updates, please see the following article in the Microsoft Knowledge Base:

194504 XCON: MTA Returns NDR for Deleted Mailbox when Message Sent to DL