On 12/22/24 04:35, Torge Riedel via Mailman-users wrote:

I checked the non-members list of all my mailman3 lists and found a lot entries like "prvs=<number>=<mail>", the <mail> is always an address from @freenet.de

A quick research mentions something related to bouncing and that such mails should be blocked/filtered. But no further details.

Can you give a hint where I need to change what to block such mails and avoid that such entries floods the non-members list?

If these are in fact bounces, the mta at freenet.de is sending bounce DSNs to the list address instead of (or possibly in addition to) the list-bounces address which is the envelope sender of the mail from Mailman. This behavior is wrong, but it is beyond your control.

If you can identify a pattern in the From: address that would match these and only these mails, you could probably configure the incoming MTA to discard them. E.g., for Postfix, see https://www.postfix.org/header_checks.5.html

You might think of using Mailman's Header filters to discard the messages, but this won't keep the nonmembers from being created as the creation happens before any of those checks.

-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan