Out Of Office Suppression

Those of you who subscribe to mailing lists will no doubt have periodically received a bunch of Out Of Office replies from fellow subscribers when you have posted to the mailing list.

Previously, the best way to handle this has been to subscribe both your normal mailbox address and a public folder to the mailing list. The idea is that you subscribe your normal mailbox address with the 'NOMAIL' option that many lists provide. The mailing list posts are delivered into your public folder, but replies are sent from your mailbox address. The 'NOMAIL' option set on your normal mailbox address prevents the mailing list messages from being delivered to your mailbox. Therefore, no Out Of Office responses are sent back to other list members when set on your normal mailbox.

In Exchange 2003, it is now possible to modify the Out Of Office behaviour to help in these situations. A new registry key exists that prevents the sending of Out Of Office responses unless the recipient is explicitly listed in either the TO: or CC: fields of the message. Since mailing list posts aren't addressed explicitly to list members, the suppression of Out Of Office responses to mailing list members is achieved.

To enable this feature, add the DWORD parameter SuppressOOFsToDistributionLists with a value of 1 into the following registry location:

HKLM\System\CurrentControlSet\Services\MSExchangeIS\ParametersSystem

This key should help some mailing list members from upsetting others!