Hi all,
I can’t think of anywhere else to ask, but this knowledgeable group is as
likely as any to know what’s going on, I think.
For years and years I’ve been able to filter all of my FreeBSD mailing list
messages into a separate FreeBSD inbox with a pair of simple dovecot-sieve
rules:
if address :matches "Sender" "*ow...@freebsd.org" { fileinto
"in.freebsd"; }
elsif address :matches "Sender" "owner*@freebsd.org" { fileinto
"in.freebsd"; }
(… and similarly for most of my other mailing lists). The Sender header is
(used to be) a reliable reflection of the envelope FROM address, which reliably
tied things to the email server sending the list messages.
On about the 11th or 12th of April, a significant chunk of FreeBSD mailing list
messages, including especially the git commit messages, started showing up in
my normal INBOX, evading the filter rules.
Over the weekend I got around to investigating, and discovered that the errant
messages don’t _have_ a Sender: header. There’s a Return-Path: header that
captures the envelope-from, but I haven’t figured out how to make sieve check
that yet: it doesn’t seem to like it. Sieve documentation is spectacularly
inconclusive, but I suspect that the envelope extension might do what I want,
but that’s not really my question.
Does anyone know why the Sender: header, which used to be so reliable that I
had thought it an intrinsic part of the SMTP/MTA ecosystem, has gone away, or
is at least not ubiquitous?
I’m running dovecot and pigeonhole and postfix from ports, on stable/14 and
feeding messages in using fetchmail rather than direct SMTP: I’ve found that
exposing an SMTP endpoint requires more anti-spam fu than I've been prepared to
muster so far. Using fetchmail is clunky but it keeps me behind my ISP’s spam
filter.
Cheers,
Andrew
