On 4/5/21 6:43 AM, marcus.granath@gmail.com wrote:
So what I basically try do achieve is to have only the following addresses to be allowed to send announcements (e-mails) on the mailman3 list, and all others that are member of the mailman3 list will just receive the e-mails. The usual "announcements" are sent out as the "no-reply" address (that actually are not really part of the mailman3 list) ;-)
no-reply@abc.com ("fake address" that actually are not really part of the mailing-list) peter@abc.com david@abc.com marcus@abc.com
How to achieve this kind of filter with mailman3?
Header filters is not the way to do this.
First set both "Default action to take when a non-member posts to thelist" and "Default action to take when a member posts to the list" to either Hold for moderation or Discard (no notification). Reject is not recommended because of backscatter from spam posts with spoofed From: addresses.
Then ensure all members Moderation Action is set to None or List Default (two names for the same thing).
Now, no one can post. To allow your set of users to post, you have choices. The easy way but not secure against spoofing is to set the Maderation Action for the three allowed members to List Default and toi create a non-member for no-reply@abc.com and set it's moderation action to List Default.
The more secure way is to leave everyone moderated, set a moderator password for the list and post with an Approved: header or pseudo header. See <https://docs.mailman3.org/projects/mailman/en/latest/src/mailman/rules/docs/...>.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan