Topic Last Modified: 2007-02-27

The Microsoft® Exchange Server Analyzer Tool reads the following registry entry to determine whether out-of-office messages are being suppressed for distribution lists:


If the Exchange Server Analyzer finds the value for SuppressOOFsToDistributionLists to be greater than 0, a non-default configuration message is displayed.

When a message is sent to a mailbox that has the Out-of-Office Assistant enabled, the sender receives a message that does not have an address in the To or the Cc field, but it does have a distribution list in the Bcc field, an out-of-office message is sent to the distribution list that is in the Bcc field.

If a message is sent to a recipient, and the recipient is addressed only in the Bcc field, but not in a distribution list, and the recipient has turned on Out of Office Assistant, the recipient's mailbox store will still send an out-of-office message even though the SuppressOOFsToDistributionLists registry value is set. This limitation applies only if the recipient is addressed in the Bcc field, and the To and the Cc fields are blank. If there is at least one user in the To or Cc fields, the registry parameter on the Exchange Server computer will suppress the recipients listed in the Bcc field from generating an out-of-office message.

This article contains information about editing the registry. Before you edit the registry, make sure you understand how to restore the registry if a problem occurs. For information about how to restore the registry, view the "Restore the Registry" Help topic in Regedit.exe or Regedt32.exe.

To modify out-of-office message generation behavior

  1. Open a registry editor, such as Regedit.exe or Regedt32.exe.

  2. Navigate to: HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

  3. Right-click ParametersSystem, point to New, and then click DWORD Value.

  4. Name the new value SuppressOOFsToDistributionLists.

  5. Right-click SuppressOOFsToDistributionLists, and then click Modify.

  6. In the Value data box, type 1, and then click OK.

  7. Close the registry editor and restart the Microsoft Exchange Information Store service for the change to take effect.

Before you edit the registry, and for information about how to edit the registry, see the Microsoft Knowledge Base article 256986, "Description of the Microsoft Windows Registry" (

For more information about the SuppressOOFsToDistributionLists registry value, see the Knowledge Base article 825370, "Out-of-Office Messages Are Sent to Distribution Lists That Are in the BCC Field" (