DL Neil wrote in <2796fd95-6554-f0ef-3ad9-1eb1e99c3b36@rangi.cloud>: |On 12/01/2023 13.16, Viktor Dukhovni wrote: |> On Thu, Jan 12, 2023 at 12:46:03PM +1300, DL Neil wrote: ... |Experiment: |- from an external address and server, send a message to the 'list' account |- postfix receives the message |- logs show postfix forwards the message |- two different domains on this server receive successfully |- message also forwarded to two external domain/servers |However, when forwarding externally, postfix doesn't re-transmit with |*my* SPF, DKIM, etc, and therefore receipt will fail or be marked as |spam by competent email services.
The reason for more and more missing '[TAG]'ged Subject: lines on lists (to not modify any header but only adding the RFC 2369 header fields, changing the Sender:, errors-to as appropriate, etc), or that ugly "XY via YZ-list <list-address>" From: lines (in other cases). This is why DMARC is hated by anyone who cared, os opposed to the people of Yahoo and what who pushed that standard through, and did not start using the Author: header added in RFC 9057 -- this RFC is well worth reading in that context. |Summary: |works for in-house applications, but best not used to forward messages |from outside-sources to external domains. Do not ask me no questions as i am not in this (mailing list handling including bounces etc) in real life, let alone in conjunction with postfix configuration. One should also reread RFC 2142. And really README_FILES/VERP_README. DKIM too, one message in this thread for example covers From:Subject:Date:References:To:In-Reply-To. --steffen | |Der Kragenbaer, The moon bear, |der holt sich munter he cheerfully and one by one |einen nach dem anderen runter wa.ks himself off |(By Robert Gernhardt)
