It is possible to exclude subscribers who have complained about spam from your organization. At this time, the exclusion is only allowed via DISTRIBUTE; this does not include administrative messages.

Important: The SPAM_FEEDBACK_EXCLUDE variables are for advanced users and are only available when the LISTSERV web interface is accessed in Expert Mode.

To define in the Web Interface, expand Server Administration, then select Site Configuration.  Click the Anti-Spam button, and then define the following:

    • SPAM_FEEDBACK_EXCLUDE_LIST – This variable tells LISTSERV to exclude all of the subscribers of the Spam Feedback Loop list in question from future bulk mailings, even if subscribed to a list or targeted for a mailing via LISTSERV Maestro or home-made DISTRIBUTE job or any other channel. This does not blackhole administrative messages; therefore, the users can still receive confirmation cookies necessary to execute commands and so on.

To enable this setting, enter the name of the Spam Feedback Loop list as the value of this configuration variable. For example, for a list named Spam-Feedback:


By default, SPAM_FEEDBACK_EXCLUDE_LIST is not set (that is, no Spam Feedback Loop lists are defined for subscriber exclusion).

Note: L-Soft does not recommend defining multiple Spam Feedback Loop lists. For maximum performance, this variable is only intended for use with one list. Then, you can ADD anyone that you want to exclude to this list. (Make sure to set Default-Options= for this list to include the NOMAIL setting.)

    • SPAM_FEEDBACK_EXCLUDE_ALLOW – This variable enables LISTSERV instances on this CIDR range to query the exclusion list managed by this LISTSERV instance. Use this setting in the instance running the Spam Feedback Loop, and in this instance only. For example:


By default, SPAM_FEEDBACK_EXCLUDE_ALLOW is not set (that is, no other LISTSERV instances are allowed to query this LISTSERV instance's exclusion list).

SPAM_FEEDBACK_EXCLUDE_SERVER – This variable is intended to be set in any LISTSERV instance(s) which is/are sharing the feedback loop.  It should NOT be set on the LISTSERV instance where the feedback loop is running.  The value is the hostname (plus optional TCPGUI port number) of the instance that operates the Spam Feedback Loops. The optional port number must match the TCPGUI port for the feedback loop instance if the default value for TCPGUI_PORT on that instance has been changed.  Examples:

If TCPGUI_PORT is not set, or is set to 2306 (the default):


If TCPGUI_PORT is set to any non-default value, e.g., 23006:


By default, SPAM_FEEDBACK_EXCLUDE_SERVER is not set.