Revision 2 as of 2008-03-07 18:23:05

Clear message

Backscatter

PROBLEM: Mailman comes out of the box ready to backscatter spam people.

RESOLUTION:

  1. Don't create backscatter aliases for subscribe/unsubscribe/etc by default. Nearly everyone uses web based signup.
  2. Discard or hold messages from non-subscribers by default. 

DETAILS:

Removing aliases depends on the installation method.

The normal default setting for new lists is to hold messages from non-members. If appropriate, you can change this default to discard by putting

DEFAULT_GENERIC_NONMEMBER_ACTION = 3

in mm_cfg.py, and of course, you can change generic_nonmember_action for any specific list after it is created.

Also, if generic_nonmember_action for a list is hold, you can consider setting the list's respond_to_post_requests to No. There is no configuration setting to make this No by default for new lists. Note however that the number of such autoresponses to a single address is limited to MAX_AUTORESPONSES_PER_DAY which defaults to 10, but can be set as low as 1 in mm_cfg.py.