Topic Last Modified: 2006-08-21

The Microsoft® Exchange Server Analyzer Tool queries the following attributes for each user object in all domains found in the Active Directory® directory service to determine whether any mailboxes in the domains have delivery restrictions set that are based on distribution group membership:


Controls whether messages are accepted or rejected by default. When set to the default setting of 1, messages from everyone are accepted.


Contains the DNs of distribution lists (DL) whose members may not send to this recipient.


Contains the DNs of distribution lists (DL) whose members may send to this recipient.

If the Exchange Server Analyzer determines that there are mailboxes in the domain that have delivery restrictions set based on distribution group membership, the Exchange Server Analyzer displays a warning.

This warning indicates that delivery restrictions based on distribution group membership may affect Exchange Server mail flow performance.

By default, the categorizer recursively expands distribution groups and checks restrictions for each message that passes through the system.

When the message categorizer sends mail to a user who accepts or denies messages from a distribution group, the message categorizer has to expand the membership of the distribution group, obtain the full list of DNs of the members, and then compare the list of DNs to the list sender’s DNs. An access operation or a deny operation occurs when a DN appears on both lists. If a distribution group is nested in another distribution group, the nested distribution is also expanded.

To address this warning:

For More Information

For more information about non-hierarchal restriction checking, see Consider non-hierarchical restriction checking.

For more information about the effect of distribution group restriction on Exchange Server mail flow, see the following Microsoft Knowledge Base articles: